Fix #9648: add missing commas in crash message

src/saveload/afterload.cpp

@@ -393,8 +393,8 @@ static void CDECL HandleSavegameLoadCrash(int signum)
 			"or older version.\n"
 			"It will load a NewGRF with the same GRF ID as the missing NewGRF.\n"
 			"This means that if the author makes incompatible NewGRFs with the\n"
-			"same GRF ID OpenTTD cannot magically do the right thing. In most\n"
-			"cases OpenTTD will load the savegame and not crash, but this is an\n"
+			"same GRF ID, OpenTTD cannot magically do the right thing. In most\n"
+			"cases, OpenTTD will load the savegame and not crash, but this is an\n"
 			"exception.\n"
 			"Please load the savegame with the appropriate NewGRFs installed.\n"
 			"The missing/compatible NewGRFs are:\n");