Update xml/issue4051.xml

Co-authored-by: Jonathan Wakely <[email protected]>

Author: tomaszkam

xml/issue4051.xml

@@ -66,7 +66,7 @@ Related vendor issues:
 Set priority to 3 after reflector poll.
 </p>
 <p>
-We should preffer rejecting undefined expression at compile time,
+We should prefer rejecting the undefined expression at compile time,
 rather than leading to UB at runtime.
 </p>
 <p>