do not ast_hangup() on a NULL channel.

In the original code this would happen in the case of
	o->forwards >=  AST_MAX_FORWARDS

Likely an 1.2/1.4 isse as well - please someone have a look,
while I am hunting a few more similar panics now.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@47880 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_dial.c

@@ -505,9 +505,9 @@ static void do_forward(struct dial_localuser *o,
 				ast_set_callerid(c, S_OR(in->macroexten, in->exten), get_cid_name(cidname, sizeof(cidname), in), NULL);
 			}
 		}
+		/* Hangup the original channel now, in case we needed it */
+		ast_hangup(c);
 	}
-	/* Hangup the original channel now, in case we needed it */
-	ast_hangup(c);
 }
 
 /* argument used for some functions. */