remove or comment empty conditional branches

some empty conditional branches which contained a semicolon were
"fixed" by clang-format to contain nothing. add comments to prevent this.

bin/named/zoneconf.c

@@ -1647,6 +1647,7 @@ named_zone_configure(const cfg_obj_t *config, const cfg_obj_t *vconfig,
 			} else if (strcasecmp(arg, "maintain") == 0) {
 				allow = maint = true;
 			} else if (strcasecmp(arg, "off") == 0) {
+				/* Default */
 			} else {
 				INSIST(0);
 				ISC_UNREACHABLE();
@@ -1801,6 +1802,7 @@ named_zone_configure(const cfg_obj_t *config, const cfg_obj_t *vconfig,
 				dns_zone_setkeyopt(zone, DNS_ZONEKEY_NORESIGN,
 						   true);
 			} else if (strcasecmp(arg, "maintain") == 0) {
+				/* Default */
 			} else {
 				INSIST(0);
 				ISC_UNREACHABLE();

lib/dns/rdata/in_1/wks_11.c

@@ -78,7 +78,7 @@ fromtext_in_wks(ARGS_FROMTEXT) {
 	isc_token_t token;
 	isc_region_t region;
 	struct in_addr addr;
-	char *e;
+	char *e = NULL;
 	long proto;
 	unsigned char bm[8 * 1024]; /* 64k bits */
 	long port;
@@ -138,8 +138,7 @@ fromtext_in_wks(ARGS_FROMTEXT) {
 				     false));
 
 	proto = strtol(DNS_AS_STR(token), &e, 10);
-	if (*e == 0) {
-	} else if (!mygetprotobyname(DNS_AS_STR(token), &proto)) {
+	if (*e != '\0' && !mygetprotobyname(DNS_AS_STR(token), &proto)) {
 		CHECKTOK(DNS_R_UNKNOWNPROTO);
 	}
 
@@ -175,9 +174,8 @@ fromtext_in_wks(ARGS_FROMTEXT) {
 		}
 
 		port = strtol(DNS_AS_STR(token), &e, 10);
-		if (*e == 0) {
-		} else if (!mygetservbyname(service, ps, &port) &&
-			   !mygetservbyname(DNS_AS_STR(token), ps, &port))
+		if (*e != 0 && !mygetservbyname(service, ps, &port) &&
+		    !mygetservbyname(DNS_AS_STR(token), ps, &port))
 		{
 			CHECKTOK(DNS_R_UNKNOWNSERVICE);
 		}

lib/dns/zoneverify.c

@@ -1611,6 +1611,7 @@ check_dnskey(vctx_t *vctx) {
 		is_ksk = ((dnskey.flags & DNS_KEYFLAG_KSK) != 0);
 
 		if ((dnskey.flags & DNS_KEYOWNER_ZONE) == 0) {
+			/* Non zone key, skip. */
 		} else if ((dnskey.flags & DNS_KEYFLAG_REVOKE) != 0) {
 			if ((dnskey.flags & DNS_KEYFLAG_KSK) != 0 &&
 			    !dns_dnssec_selfsigns(&rdata, vctx->origin,