Nothing in the API actually changed, but the project->file_patterns
fields used not to be set or used at all; so bump the API to let a
plugin depend on this field to be actually useful.

git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@5756 ea778897-0a13-0410-b9d1-a72fbfd435f5