Address C5205 compiler warning

Recent Visual Studio 2019 suggests that auto-generated base virtual
class destructor is non-virtual resulting in undefined behavior.

Signed-off-by: Simon Rozman <simon@rozman.si>

include/MSICALib.h

@@ -95,6 +95,7 @@ class COperation
 {
 public:
     COperation(int iTicks = 0);
+    virtual ~COperation();
 
     virtual HRESULT Execute(CSession *pSession) = 0;
 

src/MSICALib.cpp

@@ -34,6 +34,10 @@ COperation::COperation(int iTicks) :
 {
 }
 
+COperation::~COperation()
+{
+}
+
 
 ////////////////////////////////////////////////////////////////////////////
 // COpTypeSingleString