Update php.yml (#57)

If we'll leave this as "an named" - it's unobvious is there a typo (as it really is) or is it an error (like if you wanted to write "an unnamed" which is perfectly true)

data/php.yml

@@ -90,7 +90,7 @@ questions:
             - {value: "True",    correct: true}
             - {value: "False",   correct: false}
     -
-        question: 'True or False ? A lambda function is an named PHP function that can be stored in a variable.'
+        question: 'True or False ? A lambda function is a named PHP function that can be stored in a variable.'
         answers:
             - {value: "True",    correct: false}
             - {value: "False",   correct: true}