delete import to deprecated file

Author: erik-krogh

csharp/ql/lib/semmle/code/csharp/dataflow/internal/DelegateDataFlow.qll

@@ -8,7 +8,6 @@
 
 import csharp
 private import dotnet
-private import semmle.code.csharp.dataflow.CallContext
 private import semmle.code.csharp.dataflow.internal.DataFlowDispatch
 private import semmle.code.csharp.dataflow.internal.DataFlowPrivate
 private import semmle.code.csharp.dataflow.internal.DataFlowPublic

csharp/ql/lib/semmle/code/csharp/exprs/Call.qll

@@ -5,7 +5,6 @@
  */
 
 import Expr
-import semmle.code.csharp.dataflow.CallContext as CallContext
 private import semmle.code.csharp.dataflow.internal.DelegateDataFlow
 private import semmle.code.csharp.dataflow.internal.DataFlowDispatch
 private import semmle.code.csharp.dataflow.internal.DataFlowImplCommon