Limit password to characters or numbers

This avoids crazy characters which are hard to type

src/freedombone-utils-passwords

@@ -51,7 +51,7 @@ function enforce_good_passwords {
 }
 
 function create_password {
-    echo "$(openssl rand -base64 32 | cut -c1-${1})"
+    openssl rand -base64 32 | tr -dc A-Za-z0-9 | head -c ${1} ; echo ''
 }
 
 # NOTE: deliberately no exit 0