docs: fix typo (#3373)

docs/tendermint-core/running-in-production.md

@@ -2,7 +2,7 @@
 
 ## Database
 
-By default, Tendermint uses the `syndtr/goleveldb` package for it's in-process
+By default, Tendermint uses the `syndtr/goleveldb` package for its in-process
 key-value database. Unfortunately, this implementation of LevelDB seems to suffer under heavy load (see
 [#226](https://github.com/syndtr/goleveldb/issues/226)). It may be best to
 install the real C-implementation of LevelDB and compile Tendermint to use