Cleaner way to disable linux qt5 builds on Travis.

.travis.yml

@@ -18,6 +18,13 @@ env:
     - secure: "OI9CUjj4lTb0HwwIZU5PbECU3hLlAL6KC8KsbwohG8/O3j5fLcnmDsK4Ad9us5cC39sS11Jcd1kDP2qRcCuST/glVNhLkcjKkiQerOfd5nQ/qL4JYfz/1mfP5mdpz9jHKzpLUIG+TXkbSTjP6VVmsb5KPT+3pKEdRFZB+Pu9+J8="
     - coverity_branch: coverity_scan
 
+matrix:
+  exclude:
+    - os: linux
+      env: lt_branch=RC_1_0 gui=true qt=5
+    - os: linux
+      env: lt_branch=RC_1_0 gui=false qt=5
+
 branches:
   except:
     - search_encoding_windows
@@ -65,9 +72,6 @@ addons:
 before_install:
   # Only allow specific build for coverity scan, others will stop
   - if [ "$TRAVIS_BRANCH" = "$coverity_branch" ] && ! [ "$TRAVIS_OS_NAME" = "linux" -a "$lt_branch" = "RC_1_0" -a "$gui" = true ]; then exit ; fi
-  
-  # Only allow qt4 build for linux
-  - if [ "$TRAVIS_OS_NAME" = "linux" ] && ! [ "$qt" = 4 ]; then exit ; fi
 
   - shopt -s expand_aliases
   - if [ "$TRAVIS_OS_NAME" = "linux" ]; then export CC=gcc-4.8 CXX=g++-4.8 ; fi