entitylump: Output separator as spaces instead of tabs (#1873)

On NMRiH and possibly other games that use the Maphacks system,
entries that are modified using that system are rendered with tab
characters stripped out - see CNMRiHMapHackManager::GetEntDataString.

That results in there being no separators at all between keys and
values, as Maphacks receives the serialized string from Entity Lump
Manager.

This commit changes the key / value separator character to use
spaces instead.

This discovery upsets me greatly.

Fixes #1833.

core/logic/LumpManager.cpp

@@ -102,7 +102,7 @@ std::string EntityLumpManager::Dump() {
 		}
 		stream << "{\n";
 		for (const auto& pair : *entry) {
-			stream << '"' << pair.first << "\"	\"" << pair.second << '"' << '\n';
+			stream << '"' << pair.first << "\" \"" << pair.second << '"' << '\n';
 		}
 		stream << "}\n";
 	}