Remove defunct Little Flocker reference

Little Flocker went away when its author joined Apple and sold Little Flocker off to F-Secure where it is undergoing redesign, but not useful for this guide at this point. https://www.imore.com/little-flocker-getting-dumbed-down-good-all-mac-users

README.md

@@ -1258,7 +1258,7 @@ Some malware comes bundled with both legitimate software, such as the [Java bund
 
 See [Methods of malware persistence on Mac OS X](https://www.virusbtn.com/pdf/conference/vb2014/VB2014-Wardle.pdf) (pdf) and [Malware Persistence on OS X Yosemite](https://www.rsaconference.com/events/us15/agenda/sessions/1591/malware-persistence-on-os-x-yosemite) to learn about how garden-variety malware functions.
 
-You could periodically run a tool like [Knock Knock](https://github.com/synack/knockknock) to examine persistent applications (e.g. scripts, binaries). But by then, it is probably too late. Maybe applications such as [Block Block](https://objective-see.com/products/blockblock.html) and [Ostiarius](https://objective-see.com/products/ostiarius.html) will help. See warnings and caveats in [issue #90](https://github.com/drduh/OS-X-Security-and-Privacy-Guide/issues/90) first, however.  Using an application such as [Little Flocker](https://www.littleflocker.com/) can also protect parts of the filesystem from unauthorized writes similar to how Little Snitch protects the network (note, however, the software is still in beta and should be [used with caution](https://github.com/drduh/OS-X-Security-and-Privacy-Guide/pull/128)).
+You could periodically run a tool like [Knock Knock](https://github.com/synack/knockknock) to examine persistent applications (e.g. scripts, binaries). But by then, it is probably too late. Maybe applications such as [Block Block](https://objective-see.com/products/blockblock.html) and [Ostiarius](https://objective-see.com/products/ostiarius.html) will help. See warnings and caveats in [issue #90](https://github.com/drduh/OS-X-Security-and-Privacy-Guide/issues/90) first, however.
 
 **Anti-virus** programs are a double-edged sword -- not useful for **advanced** users and will likely increase attack surface against sophisticated threats, however possibly useful for catching "garden variety" malware on **novice** users' Macs. There is also the additional processing overhead to consider.