Don't set CFLAGS globally, just for Knot Resolver build

.travis.yml

@@ -22,7 +22,6 @@ env:
     global:
         - PKG_CONFIG_PATH="${HOME}/.local/lib/pkgconfig"
         - PATH="${HOME}/.local/bin:/usr/local/bin:${PATH}"
-        - CFLAGS="-O2 -g -fno-omit-frame-pointer -DDEBUG"
         - LD_LIBRARY_PATH="${HOME}/.local/lib"
         - DYLD_LIBRARY_PATH="${HOME}/.local/lib"
         - MALLOC_CHECK_=3
@@ -30,11 +29,11 @@ env:
 before_script:
     - BOOTSTRAP_CLEANUP=1 ./scripts/bootstrap-depends.sh ${HOME}/.local
 script:
-    - make -j2 install check V=1 COVERAGE=1 PREFIX=${HOME}/.local DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}
+    - CFLAGS="-O2 -g -fno-omit-frame-pointer -DDEBUG" make -j2 install check V=1 COVERAGE=1 PREFIX=${HOME}/.local DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}
     - ./daemon/kresd -h
     - ./daemon/kresd -V
     - echo "quit()" | ./daemon/kresd -a 127.0.0.1#53535 .
-    - make -j2 check-integration COVERAGE=1 PREFIX=${HOME}/.local DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}
+    - CFLAGS="-O2 -g -fno-omit-frame-pointer -DDEBUG" make -j2 check-integration COVERAGE=1 PREFIX=${HOME}/.local DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}
 after_success:
     - if test $TRAVIS_OS_NAME = linux; then coveralls -i lib -i daemon -x ".c" --gcov-options '\-lp'; fi
 sudo: false