Fallback manual download saving in TW280 displays two messages

[ericshulman]

As reported here:
https://groups.google.com/group/tiddlywiki/msg/86a39f3c05e816ae

When trying the direct online save in IE (ver 9, very old I guess), it
does not open a (browser) save dialogue box but instead TW gives a message:
RIGHT CLICK HERE to download/save main TiddlyWiki file
Downloading/saving main TiddlyWiki file
...and what I'm questioning is that both of these lines are links. If this
is intentional, it is a bit unclear for the user what to do. Or maybe it's
just my old IE (v9)

[ericshulman]

manualDownloadSaveFile() displays a message, "RIGHT CLICK HERE....", which is correct. However, the higher-level saveMain() then displays the second message, which is only supposed to be shown if automatic HTML5DownloadSaveFile() was triggered. The fix is to suppress the second message when the fallback manual download saving is used.