builder: do not set network.host entitlement flag if already set in buildkitd conf

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

util/confutil/container.go

@@ -32,7 +32,7 @@ func LoadConfigFiles(bkconfig string) (map[string][]byte, error) {
 	}
 
 	// Load config tree
-	btoml, err := loadConfigTree(bkconfig)
+	btoml, err := LoadConfigTree(bkconfig)
 	if err != nil {
 		return nil, err
 	}