Mode check should be added

[musicpanda]

After I had run the filecompare of the Coreupdate I changed my mind on the mode and went in a different window to the Modules section to change it from "stable" to "bleeding edge". Then I went back to Coreupdater page and pressed the "Update" button. The page initially told me that it was updating to the stable version. A bit later it ended with the attached error.

More people will do this so it shouldn't result in an error.

[getdatakick]

This is actually an expected behaviour. The comparison result showed information related to previously selected channel. If the channel was changed, the process should not be allowed to continue.

I agree that more user-friendly error message is needed, though.