Update check of GMP_NUMB_BITS declaration in assembly files.

Was broken by rename of configure variable GMP_NUMB_BITS -->
NUMB_BITS.

ChangeLog

+2017-11-12  Niels Möller  <nisse@lysator.liu.se>
+
+	* configure.ac: Update check of GMP_NUMB_BITS declaration in
+	assembly files. Was broken by rename of configure variable
+	GMP_NUMB_BITS --> NUMB_BITS.
+
 2017-11-11  Niels Möller  <nisse@lysator.liu.se>
 
 	* nettle.texinfo: Document nettle_get_hashes, nettle_get_ciphers

configure.ac

@@ -498,7 +498,7 @@ EOF
 	  dnl Note double square brackets, for extra m4 quoting.
 	  tmp_bits=`grep GMP_NUMB_BITS "$srcdir/$asm_dir/$tmp_h" \
             | sed 's/^.*GMP_NUMB_BITS(\([[0-9]]*\)).*$/\1/'`
-	  if test "$tmp_bits" && test "$tmp_bits" != "${GMP_NUMB_BITS}" ; then
+	  if test "$tmp_bits" && test "$tmp_bits" != "${NUMB_BITS}" ; then
 	     AC_MSG_WARN([skipping $tmp_h, because GMP_NUMB_BITS != $tmp_bits])
 	     continue
 	  fi