[PATCH] the '==' comparision operator is not defined by POSIX, use '=' instead in configure.ac

[Juergen Daubert]

Hello,

the '==' operator is not defined by POSIX and it's use breaks building 
of dropbear with dash and possibly other POSIX shells.

Greetings
Juergen


--- configure.ac.orig   2015-11-27 09:37:27.852925351 +0100
+++ configure.ac        2015-11-27 09:38:16.271165234 +0100
@@ -92,7 +92,7 @@
        found_crypt_func=here
        ])
 AC_SUBST(CRYPTLIB)     
-if test "t$found_crypt_func" == there; then
+if test "t$found_crypt_func" = there; then
 AC_DEFINE(HAVE_CRYPT, 1, [crypt() function])
 fi