preferences: Adjust show_deprecation default to coincide with usage

src/preferences/advanced.cpp

@@ -15,6 +15,7 @@
 #include "preferences/advanced.hpp"
 
 #include "game_config_view.hpp"
+#include "game_version.hpp"
 #include "gettext.hpp"
 #include "log.hpp"
 
@@ -39,6 +40,15 @@ advanced_manager::advanced_manager(const game_config_view& gc)
 		}
 	}
 
+	// show_deprecation has a different default on the dev branch
+	if(game_config::wesnoth_version.is_dev_version()) {
+		for(option& op : prefs) {
+			if(op.field == "show_deprecation") {
+				op.cfg["default"] = true;
+			}
+		}
+	}
+
 	std::sort(prefs.begin(), prefs.end(),
 		[](const auto& lhs, const auto& rhs) { return translation::icompare(lhs.name, rhs.name) < 0; });
 }