Fix missing arg check in geostat

geostat.cpp

@@ -152,6 +152,9 @@ int main(int argc, char** argv) {
 			case 'e':
 				heat_exp = 1;
 				break;
+			case 't':
+				trail = 1;
+				break;
 			case 'h':
 			case '?':
 			default: