missing doc

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@10736 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/resources/hudson/PluginManager/advanced.properties

-lastUpdated=Update information obtained: {0} ago
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+lastUpdated=Update information obtained: {0} ago
+uploadtext=\
+  You can upload a .hpi file to install a plugin from outside the central plugin repository.
\ No newline at end of file