On the authzperf branch: Follow-up to r1615410.
On the authzperf branch: Follow-up to r1615410.

* subversion/libsvn_subr/string.c
  (svn_stringbuf_strip_whitespace): Fix off-by-one.

git-svn-id: 1f1d32df43057f8baf3569895afdc221b0c15aad@1615421 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion