Bug 1668926 - fix missing member initialization in nsOfflineStoreCompactState. r=benc

CID 1137656 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)2. uninit_member: Non-static class member m_offlineMsgSize is not initialized in this constructor nor in any functions that it calls.

Differential Revision: https://phabricator.services.mozilla.com/D111624

--HG--
extra : rebase_source : 1e6f6b6a5413ed9aeb3dd10b7f9afd67a2e91b1f

mailnews/base/src/nsMsgFolderCompactor.cpp

@@ -901,7 +901,7 @@ nsFolderCompactState::OnDataAvailable(nsIRequest* request,
   return rv;
 }
 
-nsOfflineStoreCompactState::nsOfflineStoreCompactState() {}
+nsOfflineStoreCompactState::nsOfflineStoreCompactState() : m_offlineMsgSize(0) {}
 
 nsOfflineStoreCompactState::~nsOfflineStoreCompactState() {}