🐛 Fix Table fixed columns height 1px bug

the last th of thead has border which make it 1px higher

close ant-design/ant-design#20126

Author: afc163

src/Table.tsx

@@ -316,9 +316,8 @@ class Table<ValueType> extends React.Component<TableProps<ValueType>, TableState
       ? this.headTable.querySelectorAll('thead')
       : this.bodyTable.querySelectorAll('thead');
     const bodyRows = this.bodyTable.querySelectorAll(`.${prefixCls}-row`) || [];
-    const fixedColumnsHeadRowsHeight = [].map.call(
-      headRows,
-      (row: HTMLElement) => row.getBoundingClientRect().height || 'auto',
+    const fixedColumnsHeadRowsHeight = [].map.call(headRows, (row: HTMLElement) =>
+      row.getBoundingClientRect().height ? row.getBoundingClientRect().height - 1 : 'auto',
     );
     const state = this.store.getState();
     const fixedColumnsBodyRowsHeight = [].reduce.call(