Apply suggestions from code review

Co-authored-by: Anders Schack-Mulligen <aschackmull@users.noreply.github.com>

java/ql/lib/semmle/code/java/ConflictingAccess.qll

@@ -263,7 +263,6 @@ class ClassAnnotatedAsThreadSafe extends Class {
       not m0.isPublic() and
       c.getCallee().getSourceDeclaration() = m0 and
       c = e and
-      // consider allowing idempotent monitors
       not Monitors::locallyMonitors(e, monitor) and
       m.getDeclaringType() = this
     )

java/ql/src/Likely Bugs/Concurrency/ThreadSafe.ql

@@ -41,7 +41,7 @@ predicate not_fully_monitored_field(
     cls.has_public_write_access(f)
   ) and
   msg =
-    "The field $@ is not properly synchronized in that no single monitor covers all accesses, but the class $@ is annotated as @ThreadSafe." and
+    "This field is not properly synchronized in that no single monitor covers all accesses, but the class $@ is annotated as @ThreadSafe." and
   cls_name = cls.getName()
 }