Update c3.js and c3.min.js

c3.js

@@ -1037,7 +1037,7 @@
             parsedDate = date;
         } else if (typeof date === 'string') {
             parsedDate = $$.dataTimeFormat($$.config.data_xFormat).parse(date);
-        } else if (typeof date === 'number' || !isNaN(date)) {
+        } else if (typeof date === 'number' && !isNaN(date)) {
             parsedDate = new Date(+date);
         }
         if (!parsedDate || isNaN(+parsedDate)) {