.travis.yml: install libc6-dbg:i386 to run valgrind on 32-bit

.travis.yml

@@ -17,7 +17,7 @@ env:
 before_install:
   - sudo add-apt-repository -y ppa:codegear/release
   - sudo apt-get update -qq
-  - sudo apt-get install -qq premake4 valgrind g++-multilib
+  - sudo apt-get install -qq premake4 valgrind g++-multilib libc6-dbg:i386
 
 install: true
 
@@ -29,7 +29,7 @@ script:
   - make -C build/gmake -f example.make config=${CONF}${BITS}
   - pushd bin
   -  ./unittest_${CONF}_x${BITS}_gmake
-  - if [ "$BITS" = 64 ]; then valgrind --leak-check=full --error-exitcode=1 ./unittest_${CONF}_x${BITS}_gmake; fi
+  - valgrind --leak-check=full --error-exitcode=1 ./unittest_${CONF}_x${BITS}_gmake
   - if [ "$CONF" = "release" ]; then ./perftest_${CONF}_x${BITS}_gmake; fi
   - popd
   - ./build/travis-doxygen.sh;