Return early if json parsing fails

Fixes #505

src/log_format_loader.cc

@@ -842,6 +842,10 @@ void load_formats(const std::vector<std::string> &extra_paths,
         load_from_path(*path_iter, errors);
     }
 
+    if (!errors.empty()) {
+        return;
+    }
+
     uint8_t mod_counter = 0;
 
     vector<external_log_format *> alpha_ordered_formats;

src/yajl/yajl_parser.c

@@ -115,7 +115,7 @@ yajl_render_error_string(yajl_handle hand, const unsigned char * jsonText,
         for (i=0;i<spacesNeeded;i++) text[i] = ' ';
 
         for (;start < end;start++, i++) {
-            if (jsonText[start] != '\n' && jsonText[start] != '\r')
+            if (jsonText[start] != '\n' && jsonText[start] != '\r' && jsonText[start] != '\t')
             {
                 text[i] = jsonText[start];
             }