Skip leading whitespace in style name.

Found by Clang-Tidy. The intent seems to have been to skip all leading
whitespace in the 'style' string, but instead this loop was an odd
looking no-op. Remove the 'break' from the loop so that it will
continue until end of string or a non-space character is found.
10 jobs for skip_leading_style_whitespace in 42 minutes and 40 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #5981141
gst-macos-10.15
meson macos

00:02:53

passed #5981138
meson-mingw-w64-build

00:05:58

manual #5981142
docker windows 1809 allowed to fail manual
meson msys2
passed #5981136
meson-shared-build

00:41:59

passed #5981137
meson-static-build

00:05:50

passed #5981139
docker windows 1809
meson vs2017 amd64

00:01:26

passed #5981140
docker windows 1809
meson vs2017 x86

00:01:26

passed #5981135
mingw-build

00:06:22

passed #5981133
shared-build

00:42:40

passed #5981134
static-build

00:41:15