Reapply coordinate fix patch

    commit e452707
    Author: Kenji Rikitake <kenji.rikitake@acm.org>
    Date:   Tue Feb 18 09:33:55 2014 +0900

        Update computer.c

        * Fix quadrant coordinate boundary in the course calculation

computer.c

@@ -175,10 +175,10 @@ computer(int v __unused)
 				tqy = Ship.quady;
 			} else {
 				ix = getintpar("Quadrant");
-				if (ix < 0 || ix >= NSECTS)
+				if (ix < 0 || ix >= NQUADS)
 					break;
 				iy = getintpar("q-y");
-				if (iy < 0 || iy >= NSECTS)
+				if (iy < 0 || iy >= NQUADS)
 					break;
 				tqx = ix;
 				tqy = iy;