Made a sentence slightly more english

GTheron · GTheron · commit 9c9c93e2384b · 2015-09-14T11:51:49.000+02:00
Replaced "Even more" with "What's more" to make a sentence "more english".
diff --git a/components/http_foundation/introduction.rst b/components/http_foundation/introduction.rst
@@ -464,7 +464,7 @@ represented by a PHP callable instead of a string::
     you must call ``ob_flush()`` before ``flush()``.
 
     Additionally, PHP isn't the only layer that can buffer output. Your web
-    server might also buffer based on its configuration. Even more, if you
+    server might also buffer based on its configuration. What's more, if you
     use fastcgi, buffering can't be disabled at all.
 
 .. _component-http-foundation-serving-files:
