Use default HAVE_SIGSETJMP symbol description

When AC_DEFINE is called after some macro that has already defined the
symbol with description (help text), it can be called with two arguments
to make things easier.

[ci skip]

Author: petk

Zend/Zend.m4

@@ -151,7 +151,7 @@ AC_CHECK_FUNCS(getpid kill pthread_getattr_np pthread_attr_get_np pthread_get_st
 dnl Check for sigsetjmp. If it's defined as a macro, AC_CHECK_FUNCS won't work.
 AC_CHECK_FUNCS([sigsetjmp],,
   [AC_CHECK_DECL([sigsetjmp],
-    [AC_DEFINE([HAVE_SIGSETJMP],[1],[Define to 1 if you have the 'sigsetjmp' function.])],,
+    [AC_DEFINE([HAVE_SIGSETJMP], [1])],,
     [#include <setjmp.h>])])
 
 dnl Test whether the stack grows downwards