keepassxc: fix darwin build

- Removed the unnecessary libmicrohttpd dependency, which doesn't
  build on macOS. KeepassXC removed this dependency in 2.1.2
- Fixed a compiler error related to the Touch ID feature by adding a
  dependency on the LocalAuthentication framework

pkgs/os-specific/darwin/apple-sdk/frameworks.nix

@@ -70,6 +70,7 @@ with frameworks; with libs; {
   Kernel                  = [ IOKit ];
   LDAP                    = [];
   LatentSemanticMapping   = [ Carbon ];
+  LocalAuthentication     = [];
   MapKit                  = [];
   MediaAccessibility      = [ CoreGraphics CoreText QuartzCore ];
   MediaToolbox            = [ AudioToolbox AudioUnit CoreMedia ];