update config in case value changed

debian/diaspora-common.postinst

@@ -59,7 +59,29 @@ case "$1" in
     cp ${diaspora_conf_example} ${diaspora_conf_private}
 
     dbc_go diaspora-common "$@"
-     
+
+    cp -a -f ${diaspora_conf_private} ${diaspora_conf_private}.tmp
+
+    # Read from debconf db
+    db_get diaspora-common/ssl
+    diaspora_https=$RET
+    db_get diaspora-common/letsencrypt
+    diaspora_letsencrypt=$RET
+
+    # If the admin deleted or commented some variables but then set
+    # them via debconf, (re-)add them to the conffile.
+    test -z "$SERVERNAME" || grep -Eq '^ *SERVERNAME=' ${diaspora_conf_private} || \
+        echo "SERVERNAME=" >> ${diaspora_conf_private}
+    test -z "$diaspora_https" || grep -Eq '^ *diaspora_https=' ${diaspora_conf_private} || \
+        echo "diaspora_https=" >> ${diaspora_conf_private}
+    test -z "$diaspora_letsencrypt" || grep -Eq '^ *diaspora_letsencrypt=' ${diaspora_conf_private} || \
+        echo "diaspora_letsencrypt=" >> ${diaspora_conf_private}
+    sed -e "s/^ *SERVERNAME=.*/SERVERNAME=\"$SERVERNAME\"/" \
+        -e "s/^ *diaspora_https=.*/diaspora_https=\"$diaspora_https\"/" \
+        -e "s/^ *diaspora_letsencrypt=.*/diaspora_letsencrypt=\"$diaspora_letsencrypt\"/" \
+            < ${diaspora_conf_private} > ${diaspora_conf_private}.tmp
+        mv -f ${diaspora_conf_private}.tmp ${diaspora_conf_private}
+
 	    # Configure pod address.
     db_get diaspora-common/url
     export SERVERNAME=${RET}