Fix dead link to Wix engineering blog post (#1222)

README.md

@@ -73,8 +73,8 @@ The customer's environment imposed a high cost of new connection acquisition, an
 AKA *"What you probably didn't know about connection pool sizing"*.  Watch a video from the Oracle Real-world Performance group, and learn about why connection pools do not need to be sized as large as they often are.  In fact, oversized connection pools have a clear and demonstrable *negative* impact on performance; a 50x difference in the case of the Oracle demonstration.  [Read on to find out](https://github.com/brettwooldridge/HikariCP/wiki/About-Pool-Sizing).
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 #### WIX Engineering Analysis
-<a href="http://engineering.wix.com/2015/04/28/how-does-hikaricp-compare-to-other-connection-pools/"><img width="180" align="left" src="https://github.com/brettwooldridge/HikariCP/wiki/Wix-Engineering.png"></a>
-We'd like to thank the guys over at WIX for the unsolicited and deep write-up about HikariCP on their [engineering blog](http://engineering.wix.com/2015/04/28/how-does-hikaricp-compare-to-other-connection-pools/).  Take a look if you have time.
+<a href="https://www.wix.engineering/blog/how-does-hikaricp-compare-to-other-connection-pools"><img width="180" align="left" src="https://github.com/brettwooldridge/HikariCP/wiki/Wix-Engineering.png"></a>
+We'd like to thank the guys over at WIX for the unsolicited and deep write-up about HikariCP on their [engineering blog](https://www.wix.engineering/blog/how-does-hikaricp-compare-to-other-connection-pools).  Take a look if you have time.
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