Remove info message from MojDbLevelCursor::get

- Remove from MojDbLevelCursor::get method warning message, when key not
  found

Open-webOS-DCO-1.0-Signed-off-by: Maksym Sditanov <msditanov@luxoft.com>

Change-Id: I18e28c23443c32d18c7dd043dca4d5486143dc64
Reviewed-on: https://g2g.palm.com/2546
Reviewed-by: Build Verification
Reviewed-by: Maksym Sditanov <msditanov@luxoft.com>
Tested-by: Maksym Sditanov <msditanov@luxoft.com>
Reviewed-by: Nikolay Orliuk <norluk@luxoft.com>
Reviewed-by: Roger Stringer <roger.stringer@lge.com>