restore missed icon (fix #16466)

(cherry picked from commit 459f486)

Author: alexbruy

images/images.qrc

@@ -293,6 +293,7 @@
         <file>themes/default/mActionSelectAllTree.svg</file>
         <file>themes/default/mActionSetProjection.svg</file>
         <file>themes/default/mActionSharing.svg</file>
+        <file>themes/default/mActionSharingExport.svg</file>
         <file>themes/default/mActionSharingImport.svg</file>
         <file>themes/default/mActionShowAllLayers.svg</file>
         <file>themes/default/mActionShowBookmarks.svg</file>