De-inline destructor of CppQuickFixOperation.

Fix gcc warnings about incomplete class CppQuickFixAssistInterface
in deletion.

Change-Id: I3ecd13f134b1ace86e3b7fb1deabacbedd73f796
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cppeditor/cppquickfix.cpp

@@ -59,6 +59,9 @@ CppQuickFixOperation::CppQuickFixOperation(const CppQuickFixInterface &interface
     , m_interface(interface)
 {}
 
+CppQuickFixOperation::~CppQuickFixOperation()
+{}
+
 Snapshot CppQuickFixOperation::snapshot() const
 {
     return m_interface->snapshot();