Fixes a potential crash with database reloading (#7061)

* Fixes #7060.
* The cached YAML content will now properly reallocate the memory when the clear command is called.
Thanks to eppc0330!

src/common/database.hpp

@@ -156,6 +156,7 @@ public:
 	void clear() override{
 		TypesafeYamlDatabase<keytype, datatype>::clear();
 		cache.clear();
+		cache.shrink_to_fit();
 	}
 
 	std::shared_ptr<datatype> find( keytype key ) override{