UI: VSE: Use correct icon for enable modifier

"Enable modifier" was using the eye icon, which usually indicates
only visibility, but this actually affects render.

Also in the future there could be other visibility toggles, like
regular modifiers.

Reviewed with Falk and Dalai in person.

source/blender/makesrna/intern/rna_sequencer.cc

@@ -3835,7 +3835,7 @@ static void rna_def_modifier(BlenderRNA *brna)
   prop = RNA_def_property(srna, "enable", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_negative_sdna(prop, nullptr, "flag", STRIP_MODIFIER_FLAG_MUTE);
   RNA_def_property_ui_text(prop, "Enable", "Enable this modifier");
-  RNA_def_property_ui_icon(prop, ICON_HIDE_ON, 1);
+  RNA_def_property_ui_icon(prop, ICON_RESTRICT_RENDER_ON, 1);
   RNA_def_property_update(prop, NC_SCENE | ND_SEQUENCER, "rna_StripModifier_update");
 
   prop = RNA_def_property(srna, "show_expanded", PROP_BOOLEAN, PROP_NONE);