Only update folders after saving drafts into them

In 1f411be, I added code to tell
Thunderbird to update its index for folders when scanning them for
scheduled drafts. This caused an unexpected problem I've been hearing
about from a number of people: it's causing repeated password prompts
for accounts that people don't save their passwords for in
Thunderbird's password manager.

To avoid this problem, I'm pulling back and only updating folders
while waiting for just-saved drafts to appear in them.

utils/tools.js

@@ -246,6 +246,7 @@ var SLTools = {
     SLStatic.debug("Starting to wait for", hdr);
     let found = false;
     while (Date.now() - start < timeout) {
+      await messenger.SL3U.updateFolder(hdr.folder);
       let result = await SLTools.forAllDrafts((dHdr) => dHdr.id == hdr.id);
       if (result.some((v) => v)) {
         found = true;
@@ -294,7 +295,6 @@ var SLTools = {
       }
       let draftFolders = await SLTools.getDraftFolders(acct);
       for (let folder of draftFolders) {
-        await messenger.SL3U.updateFolder(folder);
         let page = await messenger.messages.list(folder);
         while (true) {
           if (sequential) {