avoid non-virtual-dtor warnings
```
../subprojects/phosphor-host-ipmid/include/ipmid/handler.hpp:157:7: error: base class ‘class ipmi::HandlerBase’ has accessible non-virtual destructor [-Werror=non-virtual-dtor]
../subprojects/phosphor-host-ipmid/include/ipmid/filter.hpp:37:7: error: ‘class ipmi::FilterBase’ has virtual functions and accessible non-virtual destructor [-Werror=non-virtual-dtor]
```
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib1f8befabc6ea4564524c474118b78f05403413d
diff --git a/include/ipmid/handler.hpp b/include/ipmid/handler.hpp
index 27ce370..229b0cf 100644
--- a/include/ipmid/handler.hpp
+++ b/include/ipmid/handler.hpp
@@ -107,6 +107,8 @@
public:
using ptr = std::shared_ptr<HandlerBase>;
+ virtual ~HandlerBase() = default;
+
/** @brief wrap the call to the registered handler with the request
*
* This is called from the running queue context after it has already