msuck: don't init maildir until connected

Previously, a typo in the newsgroup name would leave an empty mailbox
for a non-existent newsgroup.  This can be avoided by delaying maildir
initialization until after the NNTP server has 221ed the group.

contrib/msuck

@@ -57,10 +57,6 @@ STDOUT.sync = true
 
 ARGV.each { |group|
 
-  FileUtils.mkdir_p(File.join(dir, group, "cur"))
-  FileUtils.mkdir_p(File.join(dir, group, "new"))
-  FileUtils.mkdir_p(File.join(dir, group, "tmp"))
-
   nntp.write("GROUP #{group}\r\n")
 
   msg = nntp.gets
@@ -79,6 +75,10 @@ ARGV.each { |group|
   low = high - LIMIT + 1  if number > LIMIT - 1
   low = 1  if low <= 0
 
+  FileUtils.mkdir_p(File.join(dir, group, "cur"))
+  FileUtils.mkdir_p(File.join(dir, group, "new"))
+  FileUtils.mkdir_p(File.join(dir, group, "tmp"))
+
   have = Dir.entries(File.join(dir, group, "cur")).
            map { |f| $1.to_i if f =~ /N=(\d+)/ }.compact