chore(letter): use tt-font for pin and password

src/Handler/Utils/LMS.hs

@@ -150,4 +150,4 @@ randomLMSIdentBut banList = untilJustMaxM maxLmsUserIdentRetries getIdentOk
 randomLMSpw :: MonadIO m => m Text
 randomLMSpw = randomText extra lengthPassword
   where
-    extra = "+*:=!?#" -- you cannot distinguish ;: and ., in printed letters
+    extra = "+*:=!?#&" -- you cannot distinguish ;: and ., in printed letters

templates/letter/din5008.latex

@@ -140,8 +140,8 @@ $endif$
         \begin{textblock}{65}(84,232)%hpos,vpos
             \textcolor{black!39}{ 
               \begin{labeling}{Login:x}
-                \item[Login:] $login$
-                \item[Pin:]   $pin$    
+                \item[Login:] \texttt{$login$}
+                \item[Pin:]   \texttt{$pin$}
               \end{labeling}    
               ~}          
         \end{textblock}