Remove no longer used option from phpunit.xml

Gavin Love · Gavin Love · commit 24d380e9b6ff · 2018-06-08T13:44:09.000+01:00
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
@@ -10,7 +10,6 @@
         convertWarningsToExceptions = "true"
         processIsolation = "false"
         stopOnFailure = "true"
-        syntaxCheck = "false"
         bootstrap = "./vendor/autoload.php" >
 
     <testsuites>
