add random masterpass for sogo admin login

add required headers for sogo proxy auth with password
add SOGoEncryptionKey
add SOGoTrustProxyAuthentication only conditionally if feature is enabled

data/conf/sogo/sogo.conf

@@ -82,6 +82,4 @@
   //SOGoUIxDebugEnabled = YES;
   //WODontZipResponse = YES;
     WOLogFile = "/dev/sogo_log";
-
-    SOGoTrustProxyAuthentication = YES;
 }