Workaround in case transliterate removed all letters

This bug was hidden previously, as some results kept the separator only (a single dot ".") thus were not empty.

Author: vlakoff

src/Faker/Provider/Internet.php

@@ -96,6 +96,11 @@ public function userName()
         $username = static::transliterate($username);
         $username = strtolower(rtrim($username, '.'));
 
+        // fallback in case transliterate() doesn't support the language and removed all letters
+        if ($username === '') {
+            return $this->word;
+        }
+
         return $username;
     }
     /**
@@ -126,6 +131,11 @@ public function domainWord()
         $lastName = static::transliterate($lastName);
         $lastName = strtolower(rtrim($lastName, '.'));
 
+        // fallback in case transliterate() doesn't support the language and removed all letters
+        if ($lastName === '') {
+            return $this->word;
+        }
+
         return $lastName;
     }