[Bug c++/90005] No error produced for the wrong type of string used in gcc >= 5.0

[pawel.wrobel at nielsen dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90005

--- Comment #7 from Pawel <pawel.wrobel at nielsen dot com> ---
The "-Werror=format" solution seems to work for me - it triggers the error here
(missing .c_str()) even for the gcc >= 5.0 - leaving all the other, non-related
warnings untouched.

Thanks