Corrected an error in parsing the "defaultperimeter" statement in

tech files which incorrectly parses the syntax using five
parameters.  This syntax variant does not get used often, which
is why the error went undetected for a long time.

extract/ExtTech.c

@@ -1260,7 +1260,7 @@ ExtTechSimplePerimCap(argc, argv)
     else
 	plane2 = DBTechNoisyNamePlane(argv[argc - 2]);
 
-    if (argc > 4)
+    if (argc > 5)
     {
 	DBTechNoisyNameMask(argv[argc - 3], &subtypes);
 	TTMaskSetMask(allExtractTypes, &subtypes);