Try to fix compilation by reducing number of threads.

hiker · hiker · commit a7547dff2335 · 2015-11-09T09:14:44.000+11:00
diff --git a/.travis.yml b/.travis.yml
@@ -24,6 +24,8 @@ before_install:
 
 before_script:
   - export THREADS=`nproc`
+  # Unfortunately using all threads crashes g++: "g++: internal compiler error: Killed (program cc1plus)"
+  - exort THREADS=4
   - echo "THREADS = $THREADS"
 
 script:
