DBSQLite3: Do not raise in destructor
DBSQLite3: Do not raise in destructor

Throwing exception from destructor is not recommended and generates lots
of warnings during compilation.
Don't use macro SQLRES, and:
 - ignore return code of sqlite3_finalize (of no interest here)
 - log to stderr sqlite3_close failure

minetest/minetestmapper,minetest/minetestmapper,minetest/minetestmapper,minetest/minetestmapper