Minor, remove read check in WriteThroughScope

Without this, it's difficult to debug errors related to writing to the already
locked scope: if you set a conditional breakpoint in checkMayRead() on a
scope's toString(), its toString() will call getContainingDeclaration(), which
will call checkMayRead() again, resulting in StackOverflowError

compiler/frontend/src/org/jetbrains/jet/lang/resolve/scopes/WriteThroughScope.java

@@ -56,8 +56,6 @@ public class WriteThroughScope extends WritableScopeWithImports {
     @Override
     @NotNull
     public DeclarationDescriptor getContainingDeclaration() {
-        checkMayRead();
-
         return writableWorker.getContainingDeclaration();
     }