involute_gears.scad has improper pitch check

[SirNate0]

Somehow the check got broken or out of order. The if statement would probably work fine if it were below the ternary operator setting the circular_pitch, or it should check for the diametral_pitch being undef as well.

MCAD/involute_gears.scad

Lines 321 to 325 in bd0a7ba

	if (circular_pitch==undef)
	echo("MCAD ERROR: gear module needs either a diametral_pitch or circular_pitch");
	//Convert diametrial pitch to our native circular pitch
	circular_pitch = (circular_pitch!=undef?circular_pitch:pi/diametral_pitch);