meson: static linking of tools needs gmodule_dep

Add gmodule_dep (analog to gstreamer/tools/meson.build).

Fixes:

.../bin/ld: .../usr/lib/libgstreamer-1.0.a(gstplugin.c.o): in function `gst_plugin_register_func':
gstplugin.c:(.text+0x3bc): undefined reference to `g_module_make_resident'
.../bin/ld: .../usr/lib/libgstreamer-1.0.a(gstplugin.c.o): in function `_priv_gst_plugin_load_file_for_registry':
gstplugin.c:(.text+0x1228): undefined reference to `g_module_supported'
.../bin/ld: gstplugin.c:(.text+0x126c): undefined reference to `g_module_open'
.../bin/ld: gstplugin.c:(.text+0x1368): undefined reference to `g_module_symbol'
.../bin/ld: gstplugin.c:(.text+0x1494): undefined reference to `g_module_supported'
.../bin/ld: gstplugin.c:(.text+0x17f4): undefined reference to `g_module_close'
.../bin/ld: gstplugin.c:(.text+0x1a2c): undefined reference to `g_module_error'