core: update simplexmq (bound the time a dead connection takes to fail)

TCP keep-alive probes are only sent while there is no unacknowledged data, so a
connection that died with data in flight is only reported as failed when the OS
gives up retransmitting - about 15 minutes on Linux and Android. The pinned
simplexmq sets TCP_USER_TIMEOUT (TCP_RXT_CONNDROPTIME on Darwin) to the
keep-alive detection time when the client asks for it, so such a connection
fails after the same time as an idle one.

It is off unless the client sets it, and it is not set for connections via a
SOCKS proxy - the socket is then connected to the proxy, and a slow circuit
should not fail the connection.

cabal.project

@@ -21,7 +21,7 @@ constraints: zip +disable-bzip2 +disable-zstd
 source-repository-package
     type: git
     location: https://github.com/simplex-chat/simplexmq.git
-    tag: e24d537eaaa32230eec1fefcd957d474d7b8d4d5
+    tag: 84381e0ea528f7812ebe725d8f0b5dc638efa6b4
 
 source-repository-package
     type: git

scripts/nix/sha256map.nix

@@ -1,5 +1,5 @@
 {
-  "https://github.com/simplex-chat/simplexmq.git"."e24d537eaaa32230eec1fefcd957d474d7b8d4d5" = "1ximwqi1jaiq1ml05y0mcsrgvabhp5is1ry2h91w5jjarjb1a5fj";
+  "https://github.com/simplex-chat/simplexmq.git"."84381e0ea528f7812ebe725d8f0b5dc638efa6b4" = "0zw6rxzs04fhc65zac8r42n7lk4947lx9809qdrgrcpf8l24pyrc";
   "https://github.com/simplex-chat/hs-socks.git"."a30cc7a79a08d8108316094f8f2f82a0c5e1ac51" = "0yasvnr7g91k76mjkamvzab2kvlb1g5pspjyjn2fr6v83swjhj38";
   "https://github.com/simplex-chat/direct-sqlcipher.git"."2330df3dc8c4b660674d3c02d76bb86f66c2abee" = "11pfj1vqsjdl26nplkr2l6z1xj7cn153qijj5gknmlzq3krn7x1i";
   "https://github.com/simplex-chat/sqlcipher-simple.git"."a46bd361a19376c5211f1058908fc0ae6bf42446" = "1z0r78d8f0812kxbgsm735qf6xx8lvaz27k1a0b4a2m0sshpd5gl";