Follow-up to r18602: fix cmdline client dependency.
Follow-up to r18602: fix cmdline client dependency.

* build.conf (svn): Add libsvn_diff to depending library list.

Approved by: lundblad

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion