Fix more statement not reachable warnings

[Timoses]

Removed buildRequirements "silenceWarnings" in dub.sdl to identify more warnings.

Only 2 else (static) statements added.

[jacob-carlborg]

Does this fix all warnings? In that case the change can include removing buildRequirements "silenceWarnings".

[Timoses]

I suppose it does, as I ran dub test with buildRequirements "silenceWarnings" removed (checked compiler arguments with dub test -v and it compiled with -w).
I've added another commit with the change.

[jacob-carlborg]

Thanks.