Update alpine-vaultwarden-v5-install.sh

match input if it's "y" or "yes" (case-insensitive)
change  `=~` operator in favor of  `grep -Ei` in Alpine Linux

install/alpine-vaultwarden-v5-install.sh

@@ -74,7 +74,7 @@ trap - ERR
 if ping -c 1 -W 1 1.1.1.1 &> /dev/null; then msg_ok "Internet Connected"; else
   msg_error "Internet NOT Connected"
     read -r -p "Would you like to continue anyway? <y/N> " prompt
-    if [[ "${prompt,,}" =~ ^(y|yes)$ ]]; then
+    if echo "$prompt" | grep -Ei "^(y|yes)$" > /dev/null; then
       echo -e " ⚠️  ${RD}Expect Issues Without Internet${CL}"
     else
       echo -e " 🖧  Check Network Settings"