specfile: re-enable building with libsigsegv library

In very old versions of Fedora, it was enabled to build gawk with this
  library. More about this library can be found here:

  https://www.gnu.org/software/libsigsegv/

  However, because of the BZ #524795 it was eventually disabled as a
  kind of workaround. It was then forgotten and was never re-enabled
  again. Even emacs developers noticed that in their's mailing list:

  https://lists.gnu.org/archive/html/emacs-devel/2014-09/msg00238.html

  They used this mistake as an argument, which was incorrect, but mainly
  was not right (nor cool :)). And because vanilla build of gawk, as
  well as Debian-like distributions, uses this feature, it was enabled
  again. AFAIK, there are no security implications that should prevent
  use of this library.

gawk.spec

@@ -12,6 +12,8 @@ Source0: http://ftp.gnu.org/gnu/gawk/gawk-%{version}.tar.xz
 # taken from random.c, 2014-07-12
 Source1: BSD.txt
 Source2: https://www.gnu.org/licenses/lgpl-2.1.txt
+Requires: libsigsegv
+BuildRequires: libsigsegv-devel
 Requires(post): /sbin/install-info
 Requires(preun): /sbin/install-info
 Conflicts: filesystem < 3
@@ -34,7 +36,7 @@ considered to be a standard Linux tool for processing text.
 cp -a %{SOURCE1} %{SOURCE2} .
 
 %build
-%configure --with-libsigsegv-prefix=no
+%configure
 make %{?_smp_mflags}
 
 %check