Bump water flooding savegame version and clear states on load

src/saveload/afterload.cpp

@@ -3903,6 +3903,14 @@ bool AfterLoadGame()
 		_settings_game.economy.city_zone_4_mult = _settings_game.economy.town_zone_4_mult;
 	}
 
+	if (!SlXvIsFeaturePresent(XSLFI_WATER_FLOODING, 2)) {
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsTileType(t, MP_WATER)) {
+				SetNonFloodingWaterTile(t, false);
+			}
+		}
+	}
+
 	InitializeRoadGUI();
 
 	/* This needs to be done after conversion. */

src/saveload/extended_ver_sl.cpp

@@ -146,7 +146,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_INDUSTRY_CARGO_ADJ,     XSCF_IGNORABLE_UNKNOWN,   1,   1, "industry_cargo_adj",        nullptr, nullptr, nullptr        },
 	{ XSLFI_REALISTIC_TRAIN_BRAKING,XSCF_NULL,                2,   2, "realistic_train_braking",   nullptr, nullptr, "VLKA"         },
 	{ XSLFI_INFLATION_FIXED_DATES,  XSCF_IGNORABLE_ALL,       1,   1, "inflation_fixed_dates",     nullptr, nullptr, nullptr        },
-	{ XSLFI_WATER_FLOODING,         XSCF_NULL,                1,   1, "water_flooding",            nullptr, nullptr, nullptr        },
+	{ XSLFI_WATER_FLOODING,         XSCF_NULL,                2,   2, "water_flooding",            nullptr, nullptr, nullptr        },
 	{ XSLFI_MORE_HOUSES,            XSCF_NULL,                1,   1, "more_houses",               nullptr, nullptr, nullptr        },
 	{ XSLFI_CUSTOM_TOWN_ZONE,       XSCF_IGNORABLE_UNKNOWN,   1,   1, "custom_town_zone",          nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker