Fix a typo in swig-bindings related build-time error messages.

* build/ac-macros/swig.m4:
  (SWIG_PY_ERRMSG, SWIG_PL_ERRMSG, SWIG_RB_ERRMSG): specfied -> specified


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1910117 13f79535-47bb-0310-9956-ffa450edef68
1 file changed