Add setting to enable multiple churches/stadiums in scenario editor

See: #177

src/table/settings.ini

@@ -5327,6 +5327,13 @@ str      = STR_CONFIG_SETTING_NEWS_GENERAL_INFORMATION
 strhelp  = STR_CONFIG_SETTING_NEWS_GENERAL_INFORMATION_HELPTEXT
 strval   = STR_CONFIG_SETTING_NEWS_MESSAGES_OFF
 
+[SDTC_BOOL]
+var      = scenario.multiple_buildings
+flags    = SLF_NOT_IN_SAVE | SLF_NO_NETWORK_SYNC
+def      = false
+str      = STR_CONFIG_SETTING_SCENARIO_MULTIPLE_BUILDINGS
+strhelp  = STR_CONFIG_SETTING_SCENARIO_MULTIPLE_BUILDINGS_HELPTEXT
+
 [SDTC_VAR]
 var      = gui.network_chat_box_width_pct
 type     = SLE_UINT16