Change: Available railtypes is always calculated on load, so no need to load value for old savegames (#6782)

src/company_base.h

@@ -67,8 +67,6 @@ struct CompanyProperties {
 
 	byte colour;                     ///< Company colour.
 
-	RailTypes avail_railtypes;       ///< Rail types available to the company.
-
 	byte block_preview;              ///< Number of quarters that the company is not allowed to get new exclusive engine previews (see CompaniesGenStatistics).
 
 	TileIndex location_of_HQ;        ///< Northern tile of HQ; #INVALID_TILE when there is none.
@@ -112,6 +110,7 @@ struct Company : CompanyPool::PoolItem<&_company_pool>, CompanyProperties {
 	~Company();
 
 	Livery livery[LS_END];
+	RailTypes avail_railtypes;         ///< Rail types available to this company.
 	RoadTypes avail_roadtypes;         ///< Road types available to this company.
 
 	class AIInstance *ai_instance;

src/saveload/company_sl.cpp

@@ -259,7 +259,7 @@ static const SaveLoad _company_desc[] = {
 
 	    SLE_VAR(CompanyProperties, colour,                SLE_UINT8),
 	    SLE_VAR(CompanyProperties, money_fraction,        SLE_UINT8),
-	SLE_CONDVAR(CompanyProperties, avail_railtypes,       SLE_VAR_I32 | SLE_FILE_I8,   0, 57),
+	SLE_CONDNULL(1,  0,  57), ///< avail_railtypes
 	    SLE_VAR(CompanyProperties, block_preview,         SLE_UINT8),
 
 	SLE_CONDNULL(2,  0,  93), ///< cargo_types

src/saveload/oldloader_sl.cpp

@@ -946,7 +946,7 @@ static const OldChunks _company_chunk[] = {
 
 	OCL_SVAR(  OC_UINT8, Company, block_preview ),
 	OCL_CNULL( OC_TTD, 1 ),           // Old AI
-	OCL_SVAR( OC_TTD | OC_UINT8, Company, avail_railtypes ),
+	OCL_CNULL( OC_TTD, 1 ), // avail_railtypes
 	OCL_SVAR(   OC_TILE, Company, location_of_HQ ),
 	OCL_SVAR( OC_TTD | OC_UINT8, Company, share_owners[0] ),
 	OCL_SVAR( OC_TTD | OC_UINT8, Company, share_owners[1] ),