fix in logic for detecting PR

Author: stevector

.circleci/set-up-globals.sh

@@ -32,7 +32,7 @@ echo 'export BRANCH=$(echo $CIRCLE_BRANCH | grep -v '"'"'^\(master\|[0-9]\+.x\)$
 echo 'export PR_ENV=${BRANCH:+pr-$BRANCH}' >> $BASH_ENV
 echo 'export CIRCLE_ENV=ci-$CIRCLE_BUILD_NUM' >> $BASH_ENV
 # If we are on a pull request
-if [[ $CIRCLE_BRANCH != "master" && -n ${CIRCLE_PULL_REQUEST+x} ]]
+if [[ ${CIRCLE_BRANCH} != "master" && ! -z ${CIRCLE_PULL_REQUEST} ]]
 then
 	# Then use a pr- branch/multidev
 	PR_NUMBER=${CIRCLE_PULL_REQUEST##*/}
@@ -95,4 +95,4 @@ echo "StrictHostKeyChecking no" >> "$HOME/.ssh/config"
 git config --global user.email "$GIT_EMAIL"
 git config --global user.name "Circle CI"
 # Ignore file permissions.
-git config --global core.fileMode false
+git config --global core.fileMode false