Fix the bug where stationary vehicles would also block movement caused by external factors

docs/Whats-New.md

@@ -712,6 +712,7 @@ Phobos fixes:
 - Fixed cells with `CanBeBuiltOn=true` TerrainTypes on them not being considered valid build locations by AI (by Starkku)
 - Fixed the bug where `WeaponRange.AllowWeapons` and `WeaponRange.DisallowWeapons` only support weapons listed in the `[WeaponTypes]` list (by Noble_Fish)
 - Fixed the bug where passengers, when their transport unit is removed, would cause incorrect `LimboTracker` counts due to either having their destructor called directly (bypassing `UnInit`) or nested `UnInit` calls resetting the deletion flag too early, thereby breaking auto-death and superweapon auxiliary techno checks (by NetsuNegi)
+- Fixed a bug where stationary vehicles would also block movement caused by external factors (by Noble_Fish)
 
 Fixes / interactions with other extensions:
 - Taking over Ares' AlphaImage respawn logic to reduce lags from it (by NetsuNegi)

src/Ext/Techno/Body.cpp

@@ -749,6 +749,9 @@ bool TechnoExt::IsHealthInThreshold(TechnoClass* pObject, double min, double max
 
 bool TechnoExt::CannotMove(UnitClass* pThis)
 {
+	if (pThis->LocomotorSource)
+		return false;
+
 	const auto pType = pThis->Type;
 
 	if (pType->Speed == 0)