documentation (mt_allocator): non-working link to example program

[Stefan Schweter]

Hi,

the current *libstdc++* documentation of the `mt_allocator`
implementation [1] points to a non-working link:

http://gcc.gnu.org/viewcvs/trunk/libstdc++-v3/testsuite/ext/mt_allocator/deallocate_local-6.cc?view=markup

The `gcc` prefix is missing after `viewcvs` so the correct and working
url should be corrected to:

https://gcc.gnu.org/viewcvs/gcc/trunk/libstdc++-v3/testsuite/ext/mt_allocator/deallocate_local-6.cc?view=markup


Thanks + regards,


Stefan


[1] https://gcc.gnu.org/onlinedocs/libstdc++/manual/mt_allocator_impl.html