Updated Polish translation

Former-commit-id: db48a4a4d966009d02fe8efc49a6ff6a84ff778f

_locales/pl/messages.json

@@ -92,7 +92,7 @@
 		"description": "Button title during save: 'Save progress: xx%'"
 	},
 	"buttonUploadProgressTooltip": {
-		"message": "Upload progress: ",
+		"message": "Postęp przesyłania: ",
 		"description": "Button title during save: 'Upload progress: xx%'"
 	},
 	"buttonOKBadge": {