modify _override-bootstrap.scss

https://youtrack.weseek.co.jp/issue/GW-7804
- Remove document.body.style.position = 'static';
- Remove position: fixed from modal-open class

packages/app/src/components/PageEditor/EmojiPickerHelper.ts

@@ -18,8 +18,6 @@ setStyle = ():CSSProperties => {
   const emojiPickerHeight = 420;
   const cursorPos = this.editor.cursorCoords(true);
   const editorPos = this.editor.getWrapperElement().getBoundingClientRect();
-  // Prevent body scrolls up when modal opened
-  document.body.style.position = 'static';
   // Emoji Picker bottom position exceed editor's bottom position
   if (cursorPos.bottom + emojiPickerHeight > editorPos.bottom) {
     return {

packages/app/src/styles/_override-bootstrap.scss

@@ -115,7 +115,6 @@
 
   //Modals
   .modal-open {
-    position: fixed;
     width: 100%;
     padding-right: 0 !important;
   }