[gjs] build: Remove obsolete AC_ISC_POSIX

[Philip Chimento <pchimento src gnome org>]

commit 80b88d78f26a4466c226b05867ebfd5b3aaa9121
Author: Philip Chimento <philip chimento gmail com>
Date:   Tue Sep 27 23:35:57 2016 -0700

    build: Remove obsolete AC_ISC_POSIX
    
    This macro does checks for an operating system that was end-of-lifed in
    2006.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=772027

 configure.ac |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 87ff294..5ffa436 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,7 +29,6 @@ PKG_PROG_PKG_CONFIG
 
 AC_PROG_CXX
 AX_CXX_COMPILE_STDCXX_11
-AC_ISC_POSIX
 
 LT_PREREQ([2.2.0])
 # no stupid static libraries