fix(syntax): added a space before has

Guikingone · weaverryan · commit a519d8efc4cb · 2017-12-01T13:42:34.000-05:00
diff --git a/performance.rst b/performance.rst
@@ -92,7 +92,7 @@ By default, cached paths are only stored for ``120`` seconds by default, conside
    
 .. tip::
 
-    Since PHP 7.2, the default value for ``realpath_cache_size``has been set to 4096K, feel free to delete this trick in your     ``php.ini`` file.
+    Since PHP 7.2, the default value for ``realpath_cache_size`` has been set to 4096K, feel free to delete this trick in your     ``php.ini`` file.
 
 Use Composer's Class Map Functionality
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