When disconnecting from an SMTP server, send a quit command to be a

better internet citizen. Fixes Issue 1044.

src/com/fsck/k9/mail/transport/SmtpTransport.java

@@ -330,6 +330,14 @@ public class SmtpTransport extends Transport
 
     public void close()
     {
+        try
+        {
+            executeSimpleCommand("QUIT");
+        }
+        catch (Exception e)
+        {
+
+        }
         try
         {
             mIn.close();