It seems that some commits or files were missing from the 2.2.4 release plugin,

https://github.com/jenkinsci/git-plugin/tree/git-2.2.4/src/main/resources/hudson/plugins/git/browser

is missing Assembla - but it is a valid browser.
This is fixed in master:
https://github.com/jenkinsci/git-plugin/tree/master/src/main/resources/hudson/plugins/git/browser/AssemblaWeb

but I thought it was important enough to warrant a bug.

b/hudson/listScmBrowsers.jelly:42:77: <st:include> No page found 'config.jelly' for class hudson.plugins.g
it.browser.AssemblaWeb$ASSEMBLAWEBDescriptor
...
org.apache.commons.jelly.JellyTagException: jar:file:/opt/jenkins/jenkins-wars/a
../WEB-INF/lib/jenkins-core../li
b/hudson/listScmBrowsers.jelly:42:77: <st:include> No page found 'config.jelly' for class hudson.plugins.g
it.browser.AssemblaWeb$ASSEMBLAWEBDescriptor