Fix IMAP app_voicemail compilation issue introduced in r354429

This simply fixes the compilation issue introduced in r354429 by
re-adding the 'quote' variable.

(closes issue ASTERISK-19337)
Reported by: John Taylor


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@354799 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_voicemail.c

@@ -3046,7 +3046,7 @@ static char *get_header_by_tag(char *header, char *tag, char *buf, size_t len)
 
 static char *get_user_by_mailbox(char *mailbox, char *buf, size_t len)
 {
-	char *start, *eol_pnt;
+	char *start, *eol_pnt, *quote;
 
 	if (ast_strlen_zero(mailbox))
 		return NULL;