- filter: name was reset after an update

After filter is updated its name is reset to the value of Title from
 the filter's contents, which may be ""

filter.go

@@ -193,6 +193,7 @@ func refreshFiltersIfNecessary(force bool) int {
 		var uf filter
 		uf.ID = f.ID
 		uf.URL = f.URL
+		uf.Name = f.Name
 		uf.checksum = f.checksum
 		updateFilters = append(updateFilters, uf)
 	}