[RB] remove methods, when selecting show me senders

[Ducasse]

We get an error because the message browser cannot get the windowTitle (because unknown messages).

[Ducasse]

StMessageBrowser >> windowTitle

	^ (title ifNil: [ 'Message Browser' ]), ' [' , messageList numberOfElements printString , ']'

[carolahp]

Solution proposed in NewTools PR#1124