fix PhiloGL.Program.fromShaderIds

Commit d8a63a412826fa409db78e2f5b3620e09ac1074c introduced a bug which
broke fromShaderIds.  This is specifically here:
https://github.com/senchalabs/philogl/commit/d8a63a412826fa409db78e2f5b3620e09ac1074c#diff-9589e3a0cc72e26a4814bc9ef05aa2d4R301

fromShaderIds is supposed to return a Program, but instead this function is
delegating to onSuccess.  But the arguments/options never allow an onSuccess
to be specified.

This patch removes that onSuccess call and just returns the Program.