[Minor] Add support for change SMTP from in Milter

src/libserver/milter.c

@@ -1134,6 +1134,7 @@ rspamd_milter_send_action (struct rspamd_milter_session *session,
 	case RSPAMD_MILTER_REPLYCODE:
 	case RSPAMD_MILTER_ADDRCPT:
 	case RSPAMD_MILTER_DELRCPT:
+	case RSPAMD_MILTER_CHGFROM:
 		/* Single GString * argument */
 		value = va_arg (ap, GString *);
 		SET_COMMAND (cmd, value->len + 1, reply, pos);

src/libserver/milter.h

@@ -28,6 +28,7 @@ enum rspamd_milter_reply {
 	RSPAMD_MILTER_ACCEPT = 'a',
 	RSPAMD_MILTER_CONTINUE = 'c',
 	RSPAMD_MILTER_DISCARD = 'd',
+	RSPAMD_MILTER_CHGFROM = 'e',
 	RSPAMD_MILTER_ADDHEADER = 'h',
 	RSPAMD_MILTER_CHGHEADER = 'm',
 	RSPAMD_MILTER_REJECT = 'r',