Revert "Travis CI: Update the builds to use Qbs 1.16"

This reverts commit 308aa79.

Potentially this upgrade needs more changes for a working macOS version.

(cherry picked from commit 2a38b6a)

.travis.yml

@@ -7,7 +7,7 @@ env:
   - secure: J8Y+eQD0p5YPOlhBEPFgpZzhRFjXC4phiiFtGV3JaYX34wxCsyyNhMStMqIZTBL4D9lQojfLgXODBDaqT1iSHDe1oonosnyYnGBIJElez247pjuNiSSvcAbYa9RQnwfHe8JFphQHViURbv0OfqpHHyAlHy5b8nrPYWG2xmHA5nY=
   - secure: VgouZ5cStqlgODwIuLIvIBN5gkmrP95agCS3BorLm7g/iXM4cwuaV+bov9FiSlnzcnWfpsNMsFt5xDU2Oc17N0Kyx531MIA1H5h9xdzj/IhjhLcOOqYeXt3lN2quRE2maIZDSrPVr3eY0o6xdcNkeK0jpX/mgIiSHwXOclXv+6o=
   - QT_VERSION=5.12.8
-  - QTCREATOR_VERSION=4.12.1
+  - QTCREATOR_VERSION=4.10.1
 addons:
   coverity_scan:
     project:
@@ -53,7 +53,7 @@ matrix:
     script:
     - qbs --version
     - qbs setup-toolchains --detect
-    - qbs config defaultProfile x86_64-linux-gnu-gcc-7
+    - qbs config defaultProfile gcc
     - qbs install --install-root Tiled config:release qbs.installPrefix:/usr projects.Tiled.version:$TILED_VERSION projects.Tiled.enableZstd:true
     - cp LICENSE* COPYING *md Tiled/
     after_success: