tests: make the imap server not verify user+password

... as the test cases themselves do that and it makes it easier to add
crazy test cases.

Test 800 updated to use user name + password that need quoting.

Test 856 updated to trigger an auth fail differently.

Ref: #1902

tests/data/test800

@@ -31,7 +31,7 @@ imap
 IMAP FETCH message
  </name>
  <command>
-'imap://%HOSTIP:%IMAPPORT/800/;UID=1' -u user:secret
+'imap://%HOSTIP:%IMAPPORT/800/;UID=1' -u "user*:secret{"
 </command>
 </client>
 
@@ -40,7 +40,7 @@ IMAP FETCH message
 <verify>
 <protocol>
 A001 CAPABILITY
-A002 LOGIN user secret
+A002 LOGIN "user*" "secret{"
 A003 SELECT 800
 A004 FETCH 1 BODY[]
 A005 LOGOUT

tests/data/test856

@@ -10,6 +10,9 @@ FAILURE
 #
 # Server-side
 <reply>
+<servercmd>
+REPLY PASS -ERR Login failure
+</servercmd>
 </reply>
 
 #