Don't update conkyrc directly

* By using a temp file and comparing we can avoid excessive reloading of conky

setup/linux/include_x/airootfs/etc/skel/.update_conky

@@ -1,24 +1,30 @@
 #!/bin/bash
+# vim: sts=2 sw=2 ts=2
+
+CONFIG_BASE="${HOME}/.conkyrc_base"
+CONFIG_NEW="${HOME}/.conkyrc_new"
+CONFIG_REAL="${HOME}/.conkyrc"
 
 IF_LIST=($(ip l \
   | egrep '^[0-9]+:\s+(eth|en|wl)' \
   | sed -r 's/^[0-9]+:\s+(\w+):.*/\1/' \
   | sort))
 
-# Reset conkyrc to default
-rm "${HOME}/.conkyrc"
-cp "${HOME}/.conkyrc_base" "${HOME}/.conkyrc"
+# Build new config from the default
+rm "${CONFIG_NEW}"
+cp "${CONFIG_BASE}" "${CONFIG_NEW}"
 
-# Add interfaces to conkyrc
+# Add interfaces to conkyrc_new
 for i in "${IF_LIST[@]}"; do
   if [[ "${i:0:1}" == "e" ]]; then
-    sed -i -r "s/#Network/Wired:\${alignr}\${addr $i}\n#Network/" $HOME/.conkyrc
+    sed -i -r "s/#Network/Wired:\${alignr}\${addr $i}\n#Network/" "${CONFIG_NEW}"
   else
-    sed -i -r "s/#Network/Wireless:\${alignr}\${addr $i}\n#Network/" $HOME/.conkyrc
+    sed -i -r "s/#Network/Wireless:\${alignr}\${addr $i}\n#Network/" "${CONFIG_NEW}"
   fi
 done
 
-# Remove '#Network' line to prevent duplicating lines if this script is re-run
-sed -i -r "s/#Network//" $HOME/.conkyrc
-
-# vim: sts=2 sw=2 ts=2
+# Replace config if there were changes
+if ! diff -q "${CONFIG_NEW}" "${CONFIG_REAL}" >/dev/null 2>&1; then
+  rm "${CONFIG_REAL}"
+  cp "${CONFIG_NEW}" "${CONFIG_REAL}"
+fi