When getopts is called multiple time we need to reset OPTIND. (#3475)

Not resetting OPTIND between each call of getopts skips all short args except the first one.

It fixes this automated command: 
./certbot-auto certonly --webroot -w /tmp -d example.com --agree-tos --email contact@example.com -n

Where "-w" was parsed by getopts and not "-n"

* When getopts is called multiple time we need to reset OPTIND. Issue #3459 

* Adding OPTIND reset in the certbot-auto source file

* Building new letsencrypt-auto from template

letsencrypt-auto-source/letsencrypt-auto

@@ -58,6 +58,7 @@ for arg in "$@" ; do
     --verbose)
       VERBOSE=1;;
     -[!-]*)
+      OPTIND=1
       while getopts ":hnvq" short_arg $arg; do
         case "$short_arg" in
           h)

letsencrypt-auto-source/letsencrypt-auto.template

@@ -58,6 +58,7 @@ for arg in "$@" ; do
     --verbose)
       VERBOSE=1;;
     -[!-]*)
+      OPTIND=1
       while getopts ":hnvq" short_arg $arg; do
         case "$short_arg" in
           h)