diversion: fix compilation warnings

src/modules/diversion/diversion.c

@@ -169,8 +169,6 @@ int add_diversion_uri(sip_msg_t* msg, str* reason, str* uri)
 
 int w_add_diversion(struct sip_msg* msg, char* r, char* u)
 {
-	str div_hf;
-	char *at;
 	str uri;
 	str reason;
 
@@ -235,4 +233,4 @@ int mod_register(char *path, int *dlflags, void *p1, void *p2)
 {
 	sr_kemi_modules_add(sr_kemi_diversion_exports);
 	return 0;
-}
+}