delta[3] is used with SCARA

Shoot in the dark.

Marlin/Marlin_main.cpp

 
 #ifdef SCARA
   float axis_scaling[3] = { 1, 1, 1 };    // Build size scaling, default to 1
+  static float delta[3] = { 0, 0, 0 };		
 #endif        
 
 bool cancel_heatup = false;