send content-type when LWS_WITH_RANGES=OFF

https://github.com/warmcat/libwebsockets/pull/987

With the RANGES feature disabled, lws_serve_http_file would
not add the content-type header to the response.

lib/server.c

@@ -2385,13 +2385,17 @@ lws_serve_http_file(struct lws *wsi, const char *file, const char *content_type,
 		lwsl_info("file is being provided in gzip\n");
 	}
 
+	if (
 #if defined(LWS_WITH_RANGES)
-	if (ranges < 2 && content_type && content_type[0])
+	    ranges < 2 &&
+#endif
+	    content_type && content_type[0])
 		if (lws_add_http_header_by_token(wsi, WSI_TOKEN_HTTP_CONTENT_TYPE,
 						 (unsigned char *)content_type,
 						 strlen(content_type), &p, end))
 			return -1;
 
+#if defined(LWS_WITH_RANGES)
 	if (ranges >= 2) { /* multipart byteranges */
 		strncpy(wsi->u.http.multipart_content_type, content_type,
 			sizeof(wsi->u.http.multipart_content_type) - 1);