GTK3 -> GTK4 in meson.build (#310)

Author: NamorNiradnug

src/meson.build

@@ -7,7 +7,7 @@ pkgconfig = import('pkgconfig')
 pkgconfig.generate(
   version: meson.project_version(),
   name: meson.project_name(),
-  description: 'GTK3 shell for Wayfire',
+  description: 'GTK4 shell for Wayfire',
   variables: [
     'metadatadir=' + metadata_dir,
     'sysconfdir=' + sysconf_dir,