androiddeployqt: Avoid extra modifying of gradle's *.properties files

On each run of androiddeployqt involving gradle, the "merging" of
gradle's *.properties files inserted empty lines.

Change-Id: I7a8314cd0adf4d85663f17ac22967a08cab42b91
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

src/tools/androiddeployqt/main.cpp

@@ -2544,7 +2544,7 @@ static bool mergeGradleProperties(const QString &path, GradleProperties properti
                     continue;
                 }
             }
-            file.write(line);
+            file.write(line.trimmed() + '\n');
         }
         oldFile.close();
         QFile::remove(oldPathStr);