fix codeblocks

Author: Blargian

docs/migrations/postgres/replacing-merge-tree.md

@@ -298,12 +298,12 @@ GROUP BY year
 ORDER BY year ASC
 
 ┌─year─┬─total_answers─┐
-│ 2008 │        387832 │
-│ 2009 │        1165506 │
-│ 2010 │        1755437 │
+│ 2008 │       387832  │
+│ 2009 │       1165506 │
+│ 2010 │       1755437 │
 ...
-│ 2023 │        787032 │
-│ 2024 │        127765 │
+│ 2023 │       787032  │
+│ 2024 │       127765  │
 └──────┴───────────────┘
 
 17 rows in set. Elapsed: 0.994 sec. Processed 64.65 million rows, 983.64 MB (65.02 million rows/s., 989.23 MB/s.)