Rerun build with -j1 if it fails

scripts/build-qt.sh

@@ -4,4 +4,4 @@ mkdir -p build-qt
 cd build-qt
 cp /etc/qt/config.opt .
 ../qt5/configure -redo
-make module-qtwayland
+make module-qtwayland || make module-qtwayland -j1

scripts/build-qtbase-tests.sh

 #!/bin/bash
 set -ex
 cd ~/build-qt/qtbase
-make sub-tests
+make sub-tests || make sub-tests -j1

scripts/build-qtwayland-examples.sh

 #!/bin/bash
 set -ex
 cd ~/build-qt/qtwayland
-make sub-examples
+make sub-examples || make sub-examples -j1

scripts/build-qtwayland-tests.sh

 #!/bin/bash
 set -ex
 cd ~/build-qt/qtwayland
-make sub-tests
+make sub-tests || make sub-tests -j1