Fix: RNA: Failing assert on console auto-complete

Looks like this was caused by 3de916ca25.

Steps to reproduce were:
- Switch to the Scripting workspace
- Paste:
  `C.screen.areas[5].spaces[0].rna_type.properties['show_region_asset_shelf'].`
- Press tab

The RNA property getter should always return a value, even when empty.
That's what other such getters do as well.

source/blender/makesrna/intern/rna_rna.cc

@@ -912,6 +912,9 @@ static void rna_Property_deprecated_note_get(PointerRNA *ptr, char *value)
   if (const DeprecatedRNA *deprecated = RNA_property_deprecated(prop)) {
     strcpy(value, deprecated->note);
   }
+  else {
+    value[0] = '\0';
+  }
 }
 
 static void rna_Property_deprecated_version_get(PointerRNA *ptr, int *value)