travis: remove travis_wait, causes command not found (revert https://trac.osgeo.org/grass/changeset/70350)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@70351 15284696-431f-4ddb-bdfa-cd5b030d7da7

.travis/.travis.osx.script.sh

@@ -5,7 +5,7 @@
 # brew audit -v $RECIPE
 
 ## install GRASS trunk
-travis_wait brew install --HEAD \
+brew install --HEAD \
              --enable-shared \
              --with-postgresql \
              --with-cxx \