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);