More uniformity of file write error messages

src/ProjectFileManager.cpp

@@ -307,10 +307,7 @@ bool ProjectFileManager::DoSave(const FilePath & fileName, const bool fromSaveAs
          ShowErrorDialog(
             &window,
             XO("Error Saving Project"),
-            XO("Could not save project. Perhaps %s \n"
-               "is not writable or the disk is full.\n"
-               "For tips on freeing up space, click the help button.")
-               .Format(fileName),
+            FileException::WriteFailureMessage(fileName),
             "Error:_Disk_full_or_not_writable"
             );
       return false;