travis: temporarily disabled mingw job as hot fix

Since a recent commit eolian_gen from HEAD is needed to build efl.
So far the mingw cross build avoided the double build of efl for
bootstrapping purpose and used the 1.21 package for the cross build.

This does no longer work and all Travis jobs are now failung due to
this. As a hotfix I disable the build now (Friday evening) to have
working builds over the weekend and find a better solution next week.

.travis.yml

@@ -20,10 +20,6 @@ env:
 
 jobs:
   include:
-    - env:
-      - os: linux
-      - DISTRO=Fedora28
-      - CI_BUILD_TYPE=mingw
     - env:
       - os: linux
       - DISTRO=Fedora28
@@ -74,6 +70,11 @@ jobs:
   exclude:
     - os: linux
 
+#    - env:
+#      - os: linux
+#      - DISTRO=Fedora28
+#      - CI_BUILD_TYPE=mingw
+
 services:
   - docker