couple of ICC warnings fixed

src/encoder.hpp

@@ -52,7 +52,7 @@ namespace zmq
 
         //  The destructor doesn't have to be virtual. It is mad virtual
         //  just to keep ICC and code checking tools from complaining.
-        inline ~encoder_t ()
+        inline virtual ~encoder_t ()
         {
             free (buf);
         }

src/uuid.cpp

@@ -190,8 +190,10 @@ unsigned char zmq::uuid_t::convert_byte (const char *hexa_)
         byte = *hexa_ - 'A' + 10;
     else if (*hexa_ >= 'a' && *hexa_ <= 'f')
         byte = *hexa_ - 'a' + 10;
-    else
+    else {
         zmq_assert (false);
+        byte = 0;
+    }
 
     byte *= 16;