[pan2] Fix error found by valgrind: 22, 626 (576 direct, 22, 050 indirect) bytes in 6 blocks are definitely l

[Petr Kovář <pmkovar src gnome org>]

commit d702d1be3f984b7b3ecfd1787e423704b432d215
Author: Olaf Seibert <rhialto falu nl>
Date:   Mon Mar 14 21:59:23 2016 +0100

    Fix error found by valgrind: 22,626 (576 direct, 22,050 indirect) bytes in 6 blocks are definitely lost 
in loss record 10,796 of 10,807
    
       at 0x4C2BBCF: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
       by 0x6D2F578: g_malloc (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4600.2)
       by 0x6D46762: g_slice_alloc (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4600.2)
       by 0x6D46DFD: g_slice_alloc0 (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4600.2)
       by 0x6AC0371: g_type_create_instance (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4600.2)
       by 0x6AA238A: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4600.2)
       by 0x6AA3C70: g_object_newv (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4600.2)
       by 0x790D777: ??? (in /usr/lib/x86_64-linux-gnu/libgmime-2.6.so.0.620.0)
       by 0x790E48B: g_mime_parser_construct_part (in /usr/lib/x86_64-linux-gnu/libgmime-2.6.so.0.620.0)
       by 0x54930E: pan::mime::construct_message(_GMimeStream**, int, pan::GPGDecErr&) (mime-utils.cc:1146)
       by 0x53939E: pan::ArticleCache::get_message(std::vector<pan::Quark, std::allocator<pan::Quark> > 
const&, pan::GPGDecErr&) const (article-cache.cc:433)
       by 0x47EDD5: pan::BodyPane::set_article(pan::Article const&) (body-pane.cc:1344)

 pan/usenet-utils/mime-utils.cc |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/pan/usenet-utils/mime-utils.cc b/pan/usenet-utils/mime-utils.cc
index 1d48258..616a93f 100644
--- a/pan/usenet-utils/mime-utils.cc
+++ b/pan/usenet-utils/mime-utils.cc
@@ -1201,6 +1201,7 @@ mime :: construct_message (GMimeStream    ** istreams,
       }
     }
 
+    g_object_unref (part);
   }
   g_object_unref (parser);