migrate from com.* to alternatives (#14103)

* remove github.com/unknwon/com from models

* dont use "com.ToStr()"

* replace "com.ToStr" with "fmt.Sprint" where its easy to do

* more refactor

* fix test

* just "proxy" Copy func for now

* as per @lunny

cmd/serv.go

@@ -26,7 +26,6 @@ import (
 
 	"github.com/dgrijalva/jwt-go"
 	"github.com/kballard/go-shellquote"
-	"github.com/unknwon/com"
 	"github.com/urfave/cli"
 )
 
@@ -105,7 +104,10 @@ func runServ(c *cli.Context) error {
 	if len(keys) != 2 || keys[0] != "key" {
 		fail("Key ID format error", "Invalid key argument: %s", c.Args()[0])
 	}
-	keyID := com.StrTo(keys[1]).MustInt64()
+	keyID, err := strconv.ParseInt(keys[1], 10, 64)
+	if err != nil {
+		fail("Key ID format error", "Invalid key argument: %s", c.Args()[1])
+	}
 
 	cmd := os.Getenv("SSH_ORIGINAL_COMMAND")
 	if len(cmd) == 0 {