mail_daemon: IMAP Settings.h DeleteRemoteWhenLocal forgotten prototype

this fixes broken build, sorry

Change-Id: I2d6dd152739ae1d7aefdf0c98732b9f302b90025
Reviewed-on: https://review.haiku-os.org/676
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

IMAP: make the body fetch limit setting available.

* This is set by the ProtocolConfigView -- there should really be
some constant for this.

IMAP: Use useful default without destination.

* We now use the account name as destination directory.
* Turns out that an empty string is written as destination which worked
around the GetString() solution.

imap: added Settings::MaxConnections()/IdleMode().

* Also made use of the new BMessage API for the existing methods.

IMAP: Early work in progress of main protocol class.

We need to copy the settings message.

Started working on the IMAP add-on itself.

* Renamed imap_config.cpp to ConfigView.cpp, IMAPFolderConfig.(h|cpp)
to FolderConfigWindow.(h|cpp).
* Got the latter to build.
* Added Settings class to simplify and unify the BMessage based
settings access.
* Removed the InboundProtocol[Thread] implementation from the build for now.

IMAP: make the body fetch limit setting available.

* This is set by the ProtocolConfigView -- there should really be
some constant for this.

IMAP: Use useful default without destination.

* We now use the account name as destination directory.
* Turns out that an empty string is written as destination which worked
around the GetString() solution.

imap: added Settings::MaxConnections()/IdleMode().

* Also made use of the new BMessage API for the existing methods.

IMAP: Early work in progress of main protocol class.

We need to copy the settings message.

Started working on the IMAP add-on itself.

* Renamed imap_config.cpp to ConfigView.cpp, IMAPFolderConfig.(h|cpp)
to FolderConfigWindow.(h|cpp).
* Got the latter to build.
* Added Settings class to simplify and unify the BMessage based
settings access.
* Removed the InboundProtocol[Thread] implementation from the build for now.