entitylump: Output separator as spaces instead of tabs

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";
 	}