Thrift TException Cleanup

Summary:
Destructors should be virtual or declared protected.

Reviewed By: mcslee

Revert Plan: revertible


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@664892 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/Thrift.h b/lib/cpp/src/Thrift.h
index 347ec21..89b37d0 100644
--- a/lib/cpp/src/Thrift.h
+++ b/lib/cpp/src/Thrift.h
@@ -21,7 +21,7 @@
   TException(const std::string message) :
     message_(message) {}
 
-  ~TException() throw() {}
+  virtual ~TException() throw() {}
 
   const char* what() const throw() {
     if (message_.empty()) {