Rename http2 unpacker

These classes accidentally overlapped in naming with the nghttp2
classes.  This is because this class, unlike most nghttp2 classes
doesn't end in _ptr for a type.  This changes the class name to add a
_ex to differentiate the two classes, and avoid a warning in clang.

Tested: Unit tests pass.  Code only used in unit test.

Change-Id: I91a6982264df69bc65166ab38feddc21f72cd223
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/test/http/http2_connection_test.cpp b/test/http/http2_connection_test.cpp
index 72f985c..7d6572c 100644
--- a/test/http/http2_connection_test.cpp
+++ b/test/http/http2_connection_test.cpp
@@ -51,7 +51,7 @@
 void unpackHeaders(std::string_view dataField,
                    std::vector<std::pair<std::string, std::string>>& headers)
 {
-    nghttp2_hd_inflater inflater;
+    nghttp2_hd_inflater_ex inflater;
 
     while (!dataField.empty())
     {