Fix typo in extensions.ael sample

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5927 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/extensions.ael.sample

@@ -4,7 +4,7 @@
 
 macro std-exten-ael( ext , dev ) {
         Dial(${ext}/${dev},20);
-        switch(${DIALSTATUS) {
+        switch(${DIALSTATUS}) {
         case BUSY:
                 Voicemail(b${ext});
                 break;