move use of contextTask out of columns, into commands

src/commands/CmdDuplicate.cpp

@@ -33,6 +33,8 @@
 #include <util.h>
 #include <main.h>
 
+extern Task* contextTask;
+
 ////////////////////////////////////////////////////////////////////////////////
 CmdDuplicate::CmdDuplicate ()
 {
@@ -100,6 +102,7 @@ int CmdDuplicate::execute (std::string&)
     dup.setStatus (Task::pending); // Does not inherit status.
                                    // Must occur after Task::recurring check.
 
+    contextTask = &dup;
     dup.modify (Task::modAnnotate);
 
     if (permission (format ("Duplicate task {1} '{2}'?",