Follow-up to r1064436: Fix a copy-pasto that caused an assertion failure with "svn diff --old=. --new=^/subversion/trunk":  assertion "svn_dirent_is_canonical(base, pool)" failed: file \  "subversion/libsvn_subr/dirent_uri.c", line 1010, function "svn_dirent_join"
Follow-up to r1064436:
Fix a copy-pasto that caused an assertion failure with
"svn diff --old=. --new=^/subversion/trunk":
 assertion "svn_dirent_is_canonical(base, pool)" failed: file \
 "subversion/libsvn_subr/dirent_uri.c", line 1010, function "svn_dirent_join"

* subversion/svn/diff-cmd.c
  (svn_cl__diff): We want to check if the new target is a URL. We've already
    checked the old one.

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