Spaces in zookeeper configuration files prevent zkCleanup.sh from working

Running zkCleanup.sh fails:

$ ZOOCFGDIR=/etc/zookeeper/conf /opt/zookeeper/bin/zkCleanup.sh -n 10
Path '/' does not exist.
Usage:
PurgeTxnLog dataLogDir [snapDir] -n count
 dataLogDir -- path to the txn log directory
 snapDir -- path to the snapshot directory
 count -- the number of old snaps/logs you want to keep, value should be greater than or equal to 3

This is because it fails to parse the dataDir entry from zoo.cfg:

++ grep '^[[:space:]]*dataDir=' /etc/zookeeper/conf/zoo.cfg
++ sed -e 's/.*=//'
+ ZOODATADIR=

zkCleanup.sh needs the = character to be directly next to dataDir, without space: https://github.com/apache/zookeeper/blob/release-3.4.13/bin/zkCleanup.sh#L39-L40

The template zookeeper.cfg.j2 is already written this way, but I expect merge_config is adding the extra spaces. We may need a new option to merge_config to tell it to avoid using spaces.