Fixes SSL debconf questions.

debian/jitsi-meet.config

 # certificate type choice
 db_input critical jitsi-meet/cert-choice || true
 db_go
-
-# ssl key file path
-#db_input critical jitsi-meet/cert-path-key || true
-#db_go
-
-# ssl cert file path
-#db_input critical jitsi-meet/cert-path-crt || true
-#db_go

debian/jitsi-meet.postinst

             # self-signed certificate is already in place for prosody
             :
         elif [ "$CERT_CHOICE" = 'I have a certificate and will upload the files on the server' ]; then
-            db_fset jitsi-meet/default-key "/etc/ssl/$JVB_HOSTNAME.key"
+            db_set jitsi-meet/cert-path-key "/etc/ssl/$JVB_HOSTNAME.key"
             db_input critical jitsi-meet/cert-path-key || true
             db_go
             db_get jitsi-meet/cert-path-key
             CERT_KEY="$RET"
-            db_fset jitsi-meet/default-crt "/etc/ssl/$JVB_HOSTNAME.crt"
+            db_set jitsi-meet/cert-path-crt "/etc/ssl/$JVB_HOSTNAME.crt"
             db_input critical jitsi-meet/cert-path-crt || true
             db_go
             db_get jitsi-meet/cert-path-crt
             CERT_CRT="$RET"
             # replace self-signed certificate paths with user provided ones
-            sed -i "s/ssl_certificate_key\ \/var\/lib\/prosody\/(.*)key/ssl_certificate_key\ $CERT_KEY/g" \
+            CERT_KEY_ESC=$(echo $CERT_KEY | sed 's/\./\\\./g')
+            CERT_KEY_ESC=$(echo $CERT_KEY_ESC | sed 's/\//\\\//g')
+            sed -i "s/ssl_certificate_key\ \/var\/lib\/prosody\/.*key/ssl_certificate_key\ $CERT_KEY_ESC/g" \
                 /etc/nginx/sites-available/$JVB_HOSTNAME.conf
-            sed -i "s/ssl_certificate\ \/var\/lib\/prosody\/(.*)crt/ssl_certificate\ $CERT_CRT/g" \
+            CERT_CRT_ESC=$(echo $CERT_CRT | sed 's/\./\\\./g')
+            CERT_CRT_ESC=$(echo $CERT_CRT_ESC | sed 's/\//\\\//g')
+            sed -i "s/ssl_certificate\ \/var\/lib\/prosody\/.*crt/ssl_certificate\ $CERT_CRT_ESC/g" \
                 /etc/nginx/sites-available/$JVB_HOSTNAME.conf
         fi