Code refactoring (#3011)

* Code refactoring 

read without -r will mangle backslashes
https://github.com/koalaman/shellcheck/wiki/SC2162

* Update x-ui.sh

Author: Pk-web6936

x-ui.sh

@@ -69,7 +69,7 @@ confirm_restart() {
 }
 
 before_show_menu() {
-    echo && echo -n -e "${yellow}Press enter to return to the main menu: ${plain}" && read temp
+    echo && echo -n -e "${yellow}Press enter to return to the main menu: ${plain}" && read -r temp
     show_menu
 }
 
@@ -125,8 +125,8 @@ update_menu() {
 }
 
 legacy_version() {
-    echo "Enter the panel version (like 2.4.0):"
-    read tag_version
+    echo -n "Enter the panel version (like 2.4.0):"
+    read -r tag_version
 
     if [ -z "$tag_version" ]; then
         echo "Panel version cannot be empty. Exiting."
@@ -256,7 +256,8 @@ check_config() {
 }
 
 set_port() {
-    echo && echo -n -e "Enter port number[1-65535]: " && read port
+    echo -n "Enter port number[1-65535]: "
+    read -r port
     if [[ -z "${port}" ]]; then
         LOGD "Cancelled"
         before_show_menu