Add qtenginio to merge mainlines script

Change-Id: I3f765054b9449847f30f96f451769f890a60ccd3
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>

bin/git-qt-merge-mainlines

@@ -23,6 +23,7 @@ DEFAULT_MODULE_LIST = [
     'qtconnectivity',
     'qtdeclarative',
     'qtdoc',
+    'qtenginio',
     'qtgraphicaleffects',
     'qtimageformats',
     'qtlocation',