Qbs: Use proper mimetype for qbs project files

Change-Id: I88cc3b74bff44d11b019868dc40d43788c035558
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/qbsprojectmanager/qbsprojectmanagerconstants.h

@@ -39,7 +39,7 @@ namespace Constants {
 const char PROJECT_ID[] = "Qbs.QbsProject";
 
 // MIME types:
-const char MIME_TYPE[] = "application/vnd.qtproject.qbsproject";
+const char MIME_TYPE[] = "application/x-qt.qbs+qml";
 
 // Progress reports:
 const char QBS_EVALUATE[] = "Qbs.QbsEvaluate";