Added true fallback to num_cpu_cores SunOS case

plugins/python-build/bin/python-build

@@ -156,7 +156,7 @@ num_cpu_cores() {
     num="$(sysctl -n hw.ncpu 2>/dev/null || true)"
     ;;
   SunOS )
-    num="$(getconf NPROCESSORS_ONLN 2>/dev/null)"
+    num="$(getconf NPROCESSORS_ONLN 2>/dev/null || true)"
     ;;
   * )
     num="$({ getconf _NPROCESSORS_ONLN ||