[FIXED JENKINS-22080] NPE if trying to install a plugin from the update center and either the update source or the plugin contains a '.' in its name
Merge pull request #1150 from stephenc/master

[FIXED JENKINS-22080] NPE if trying to install a plugin from the update ...
[FIXED JENKINS-22080] Braindead logic in author of original fix... corrected by same author
Merge pull request #1151 from stephenc/master

[FIXED JENKINS-22080] Braindead logic in author of original fix... corre...