Bug 1819569 - Remove msgpack cluster. r=sylvestre

Differential Revision: https://phabricator.services.mozilla.com/D171340

third_party/msgpack/moz.build

@@ -12,18 +12,14 @@ LOCAL_INCLUDES += [
 
 EXPORTS += [
     'include/msgpack.h',
-    'include/msgpack/util.h',
 ]
 
 # We allow warnings for third-party code that can be updated from upstream.
 AllowCompilerWarnings()
 
 SOURCES += [
-    'src/objectc.c',
-    'src/unpack.c',
     'src/version.c',
     'src/vrefbuffer.c',
-    'src/zone.c',
 ]
 
 FINAL_LIBRARY = 'xul'