latency: fix latency combine calculations

0 is a valid min latency so we can't use it as an unset value. Use
some large value instead and when nothing was configured, assume it
is 0.

Fixes #1839
43 jobs for master in 7 minutes and 27 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Container
passed container_fedora #16317229

00:00:15

passed container_ubuntu #16317228

00:00:13

 
  Build
passed build_meson_exact_release #16317264

00:01:15

passed build_meson_prerelease #16317263

00:02:20

passed build_on_fedora #16317231

00:02:10

passed build_on_ubuntu #16317230

00:02:13

passed build_release: [clang] #16317257

00:01:25

passed build_release: [gcc] #16317256

00:01:24

passed build_session_managers: [[]] #16317258

00:01:37

passed build_session_managers: [media-session] #16317260

00:01:40

passed build_session_managers: [media-session,wireplumber] #16317261

00:01:55

passed build_session_managers: [wireplumber] #16317259

00:01:47

passed build_session_managers: [wireplumber,media-session] #16317262

00:01:55

passed build_with_custom_options: [audiotestsrc, disabled] #16317243

00:02:54

passed build_with_custom_options: [audiotestsrc, enabled] #16317242

00:02:03

passed build_with_custom_options: [bluez5-backend-hsphfpd, disabled] #16317241

00:02:08

passed build_with_custom_options: [bluez5-backend-hsphfpd, enabled] #16317240

00:00:47

passed build_with_custom_options: [docs, disabled] #16317235

00:02:04

passed build_with_custom_options: [docs, enabled] #16317234

00:02:10

passed build_with_custom_options: [installed_tests, disabled] #16317237

00:02:18

passed build_with_custom_options: [installed_tests, enabled] #16317236

00:02:09

passed build_with_custom_options: [sdl2, disabled] #16317253

00:01:20

passed build_with_custom_options: [sdl2, enabled] #16317252

00:02:53

passed build_with_custom_options: [sndfile, disabled] #16317255

00:01:42

passed build_with_custom_options: [sndfile, enabled] #16317254

00:01:22

passed build_with_custom_options: [systemd-system-service, disabled] #16317239

00:02:01

passed build_with_custom_options: [systemd-system-service, enabled] #16317238

00:02:08

passed build_with_custom_options: [test, disabled] #16317245

00:02:00

passed build_with_custom_options: [test, enabled] #16317244

00:02:54

passed build_with_custom_options: [videotestsrc, disabled] #16317247

00:01:05

passed build_with_custom_options: [videotestsrc, enabled] #16317246

00:02:54

passed build_with_custom_options: [volume, disabled] #16317249

00:02:00

passed build_with_custom_options: [volume, enabled] #16317248

00:02:54

passed build_with_custom_options: [vulkan, disabled] #16317251

00:00:37

passed build_with_custom_options: [vulkan, enabled] #16317250

00:02:53

passed build_with_no_commandline_options: [clang] #16317233

00:01:03

passed build_with_no_commandline_options: [gcc] #16317232

00:02:10

passed valgrind #16317265

00:00:48

 
  Analysis
passed doccheck #16317268

00:01:21

passed shellcheck #16317266

00:01:33

passed spellcheck #16317267

00:01:20

 
  Pages
passed pages #16317269

00:00:13

 
  Deploy
passed pages:deploy

00:00:00