:fire: remove useless line

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index bdabc88..f48ee1f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -316,7 +316,6 @@
 
   # make sure CXX is correctly set
   - if [[ "${COMPILER}" != "" ]]; then export CXX=${COMPILER}; fi
-  - if [[ "${CXXFLAGS}" != "" ]]; then export CXXFLAGS=${CXXFLAGS}; fi
   # by default, use the single-header version
   - if [[ "${MULTIPLE_HEADERS}" == "" ]]; then export MULTIPLE_HEADERS=OFF; fi
   # by default, use implicit conversions