Fix a couple memory leaks caused by files not being closed (#1670)

Author: alranel

Diff for: arduino/security/signatures.go

@@ -42,6 +42,7 @@ func VerifyArduinoDetachedSignature(targetPath *paths.Path, signaturePath *paths
 	if err != nil {
 		panic("could not find bundled signature keys")
 	}
+	defer arduinoKeyringFile.Close()
 	return VerifySignature(targetPath, signaturePath, arduinoKeyringFile)
 }
 

Diff for: i18n/cmd/po/parser.go

@@ -31,6 +31,7 @@ func Parse(filename string) MessageCatalog {
 	}
 
 	file, err := os.Open(filename)
+	defer file.Close()
 
 	if err != nil {
 		fmt.Println(err.Error())