Debugger: Abort gdb session if no python support is found

The message will be untranslated due to the string freeze,
but better than nothing.

Task-number: QTCREATORBUG-11505

Change-Id: I6f5e65615e4c20f42ce6800b8107f923c2ae2c4f
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
Fix missing white space in German translation

Change-Id: I0b4db6f76befed238427f7fbf51fd73446dbb773
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>