The source project of this merge request has been removed.
backport fix for libgedit-gtksourceview 299.1.0
This fixes the following compiler warning (should be an error).
../gedit/plugins/quickhighlight/gedit-quick-highlight-plugin.c:96:47: warning:
implicit declaration of function ‘gtk_source_style_copy’; did you mean ‘gtk_source_style_apply’? [-Wimplicit-function-declaration]