Fix annoying assert on Windows. When a new document is created...

Fix annoying assert on Windows. When a new document is created documentcontroller will create path with an empty string. That will cause two asserts pr. new file on windows when compiled in debug mode.

kdevplatform/util/path.cpp

@@ -138,7 +138,7 @@ static QString generatePathOrUrl(bool onlyPath, bool isLocalFile, const QVector<
     // more or less a copy of QtPrivate::QStringList_join
     const int size = data.size();
 
-    if (size == 0) {
+    if (size == 0 || data.at(0).isEmpty()) {
         return QString();
     }