consistency checks fixes

src/entities/note.js

@@ -117,7 +117,6 @@ class Note extends Entity {
         return JSON.parse(content);
     }
 
-    /** @returns {Promise} */
     setContent(content) {
         if (content === null || content === undefined) {
             throw new Error(`Cannot set null content to note ${this.noteId}`);

src/entities/note_revision.js

@@ -100,7 +100,6 @@ class NoteRevision extends Entity {
         }
     }
 
-    /** @returns {Promise} */
     setContent(content) {
         // force updating note itself so that utcDateModified is represented correctly even for the content
         this.forcedChange = true;