Add .gitreview config

Change-Id: I8cc491cdde3b0e949b77583a02a222b55c8c4ca6
Reviewed-on: http://gerrit.dmdirc.com/4018
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

.gitreview

@@ -0,0 +1,5 @@
+[gerrit]
+host=dmdirc.com
+port=29418
+project=client
+defaultbranch=master