[gimp-help] Fix help id of dropshadow filter.

[Jacob Boerema <jboerema src gnome org>]

commit 1e3dc501dab90af747781b564c68202ab08cf62f
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed Sep 28 18:42:32 2022 -0400

    Fix help id of dropshadow filter.
    
    (cherry picked from commit d6fd34c2c56642266385250ecd23d15a586f7f0e)

 src/filters/light-and-shadow/drop-shadow.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/filters/light-and-shadow/drop-shadow.xml b/src/filters/light-and-shadow/drop-shadow.xml
index 34ce9831d..c62cce645 100644
--- a/src/filters/light-and-shadow/drop-shadow.xml
+++ b/src/filters/light-and-shadow/drop-shadow.xml
@@ -4,7 +4,7 @@
 <!-- section history:
   20019-01-09 j.h Create
 -->
-<sect2 xmlns:xi="http://www.w3.org/2001/XInclude"; id="gimp-filter-drop-shadow">
+<sect2 xmlns:xi="http://www.w3.org/2001/XInclude"; id="gimp-filter-dropshadow">
   <title>Drop Shadow</title>
 
   <indexterm>