Incorrect framerate calculation for animations consisting of single frame

[FreeSlave]

The following code completely ignores the fps of the model sequence if the number of frames is 1, effectively treating the sequence like if it had fps = 1.

hlsdk-portable/dlls/animation.cpp

Lines 250 to 260 in e530099

	if( pseqdesc->numframes > 1 )
	{
	*pflFrameRate = 256.0f * pseqdesc->fps / ( pseqdesc->numframes - 1 );
	*pflGroundSpeed = sqrt( pseqdesc->linearmovement[0] * pseqdesc->linearmovement[0] + pseqdesc->linearmovement[1] * pseqdesc->linearmovement[1] + pseqdesc->linearmovement[2] * pseqdesc->linearmovement[2] );
	*pflGroundSpeed = *pflGroundSpeed * pseqdesc->fps / ( pseqdesc->numframes - 1 );
	}
	else
	{
	*pflFrameRate = 256.0f;
	*pflGroundSpeed = 0.0f;
	}

It means, for example, playing the animation of 1 frame and 30 fps is slower than playing animation of 2 frames and 2 fps.

Known affected entities: voltigore in Opposing Force appears to be "stuck" in flinch animation for the full second despite it having only 1 frame and 30 fps. Basically the sequence is intended to play the pain sound via animation event, but not "freezing" the voltigore.