It's been AGES since people have stopped using numerical values such as 1..9 for priority in bugtrackers because it's ambiguous: you never know whether 1 is supposed to be the highest or lowest priority, as both conventions have historically been used. Modern decent bugtrackers use unambiguous values such as "high", "low", etc.
I thought this was an issue in SourceForge but as I reported it in https://sourceforge.net/p/forge/feature-requests/380/ they replied:
"Greetings, every field is fully customizable, so if you don't like it ask to phpMyAdmin administrators to change it."
Please do so.
Done.