Remove also the '{language}.sp.model' file on failure

perplexity_lenses/perplexity.py

@@ -11,6 +11,7 @@ class KenlmModel:
             self.model = kenlm.Model(f"{language}.arpa.bin")
         except OSError:
             os.remove(f"{language}.arpa.bin")
+            os.remove(f"{language}.sp.model")
             raise OSError("File was corrupt and should have been removed. Please, retry.")
 
     @classmethod