[gnome-shell] build: Remove C++ check

[Bastien Nocera <hadess src gnome org>]

commit 7784bc0905dcc4c63ef10f0d120701b6e542f786
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Jan 17 14:29:09 2017 +0100

    build: Remove C++ check
    
    As it's not used any more since commit
    ed99bef45841c407683cd7d353f0e2d364977261.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=762444

 configure.ac |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index d86afcc..04e2159 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,6 @@ m4_ifdef([AM_SILENT_RULES],[AM_SILENT_RULES([yes])])
 
 # Checks for programs.
 AC_PROG_CC
-AC_PROG_CXX
 
 # Initialize libtool
 LT_PREREQ([2.2.6])