[Bug libstdc++/79422] Use ACX_BUGURL for error in snprintf_lite.cc

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79422

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-02-08
   Target Milestone|---                         |8.0
     Ever confirmed|0                           |1