Squish: Update expected text in tst_git_local

Change-Id: I97a532f80b9dc2b40ec5931116b207cfaeef8f4b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

tests/system/suite_tools/tst_git_local/test.py

@@ -223,7 +223,7 @@ def main():
     mouseClick(gitEditor, rect.x+rect.width/2, rect.y+rect.height/2, 0, Qt.LeftButton)
     changed = waitForObject(":Qt Creator_DiffEditor::SideDiffEditorWidget")
     waitFor('str(changed.plainText) != "Waiting for data..."', 5000)
-    test.compare(str(changed.plainText), "Failed",
+    test.compare(str(changed.plainText), "Retrieving data failed.",
                  "Showing an invalid commit can't succeed but Creator survived.")
 
     invokeMenuItem("File", "Close All Projects and Editors")