Add fallback for fetching external ip (ipinfo.io)

If ipecho is down or the ISP is blocking it, there are no other ways to get external ip. Adding another fallback to ipinfo.io makes the issue that rtinst can't figure out the external ip less likely.

Issue: #448

scripts/rtinst

@@ -245,20 +245,23 @@ fi
 
 serveripa=$(ip route get 8.8.8.8 | awk 'NR==1 {print $7}')
 serveripb=$(wget -qO- --timeout=3 ipecho.net/plain)
+serveripc=$(wget -qO- --timeout=3 ipinfo.io/ip)
 
-if [ "$serveripa" = "$serveripb" ]; then
+if [ "$serveripa" = "$serveripb" ] || [ "$serveripa" = "$serveripc" ]; then
   serverip=$serveripa
 else
   echo "Select the IP address to use:"
   echo "1.) "$serveripa
   echo "2.) "$serveripb
+  echo "3.) "$serveripc
 
   while true
     do
       read answer
       case $answer in [1] ) serverip=$serveripa && break ;;
                       [2] ) serverip=$serveripb && break ;;
-                        * ) echo "Enter 1 or 2";;
+                      [3] ) serverip=$serveripc && break ;;
+                        * ) echo "Enter 1, 2 or 3";;
     esac
   done
 fi

scripts/rtletsencrypt

@@ -24,19 +24,22 @@ fi
 if [ $headless = 1 ]; then
   serveripa=$(ip route get 8.8.8.8 | awk 'NR==1 {print $7}')
   serveripb=$(wget -qO- ipecho.net/plain)
-  if [ "$serveripa" = "$serveripb" ]; then
+  serveripc=$(wget -qO- --timeout=3 ipinfo.io/ip)
+  if [ "$serveripa" = "$serveripb" ] || [ "$serveripa" = "$serveripc" ]; then
     serverip=$serveripa
   else
     echo "Select the IP address to use:"
     echo "1.) "$serveripa
     echo "2.) "$serveripb
+    echo "3.) "$serveripc
 
     while true
       do
         read answer
         case $answer in [1] ) serverip=$serveripa && break ;;
                         [2] ) serverip=$serveripb && break ;;
-                          * ) echo "Enter 1 or 2";;
+                        [3] ) serverip=$serveripc && break ;;
+                          * ) echo "Enter 1, 2 or 3";;
       esac
     done
   fi

scripts/rtsslcert

@@ -97,19 +97,22 @@ fi
 if [ -z $serverip ]; then
   serveripa=$(ip route get 8.8.8.8 | awk 'NR==1 {print $7}')
   serveripb=$(wget -qO- ipecho.net/plain)
-  if [ "$serveripa" = "$serveripb" ]; then
+  serveripc=$(wget -qO- --timeout=3 ipinfo.io/ip)
+  if [ "$serveripa" = "$serveripb" ] || [ "$serveripa" = "$serveripc" ]; then
     serverip=$serveripa
   else
     echo "Select the IP address to use:"
     echo "1.) "$serveripa
     echo "2.) "$serveripb
+    echo "3.) "$serveripc
 
     while true
       do
         read answer
         case $answer in [1] ) serverip=$serveripa && break ;;
                         [2] ) serverip=$serveripb && break ;;
-                          * ) echo "Enter 1 or 2";;
+                        [3] ) serverip=$serveripc && break ;;
+                        * ) echo "Enter 1, 2 or 3";;
       esac
     done
   fi