Fixed translatePlural method so if no translation exists, will defaul…

…t to using the $singular string if $number is 1, and the $plural string otherwise (had been reversed).

src/Translator/Translator.php

@@ -333,7 +333,7 @@ public function translatePlural(
                 );
             }
 
-            return ($number != 1 ? $singular : $plural);
+            return ($number == 1 ? $singular : $plural);
         }
 
         $index = $this->messages[$textDomain][$locale]