Fix piwik "maintainer:" comment formatting

library/piwik

@@ -1,4 +1,4 @@
-# maintainer [email protected]
+# maintainer: Pierre Ozoux <[email protected]> (@pierreozoux)
 
 2.16.1: git://github.com/piwik/docker-piwik.git@70bb9d02587964baee0e652cebc4fb85ac553f38
 2.16: git://github.com/piwik/docker-piwik.git@70bb9d02587964baee0e652cebc4fb85ac553f38