Set IFS only locally for read in deploy_documentation_tags.sh (#1378)

* Set IFS only locally for read

Previously IFS was set for the whole bash setting, which later affected
the word splitting when the secrets were read from the variables and
split into the openssl command.

This also tidies up the array reading - previously, the `VERSION`
variable was an array (so `echo $VERSION` would be equivalent to
`echo ${VERSION[0]}`), and it was passed to `cut`, which isn't
necessary, since it was already split.

* Include major.minor versioning in path

tools/deploy_documentation_tag.sh

@@ -24,9 +24,8 @@ echo "show current dir: "
 pwd
 
 CURRENT_TAG=`git describe --abbrev=0`
-IFS='.'
-read -ra VERSION <<< "$CURRENT_TAG"
-STABLE_VERSION=`echo $VERSION | cut -d "." -f -2`
+IFS=. read -ra VERSION <<< "$CURRENT_TAG"
+STABLE_VERSION="${VERSION[0]}.${VERSION[1]}"
 
 # Build the documentation.
 tox -edocs -- -D content_prefix=documentation/stable/"$STABLE_VERSION" -j auto