pkg/docker: set branch 5.7 and refresh [skip ci]

.gitmodules

@@ -1,6 +1,7 @@
 [submodule "pkg/docker"]
 	path = pkg/docker
 	url = https://github.com/kamailio/kamailio-ci.git
+	branch = 5.7
 [submodule "src/modules/tls_wolfssl/lib/wolfssl"]
 	path = misc/external/wolfssl/wolfssl
 	url = https://github.com/wolfSSL/wolfssl.git

pkg/docker

@@ -1 +1 @@
-Subproject commit 5c45c0f8871ceebb1a8f5308653bca924afb0d6f
+Subproject commit 064be5f078d679b0e44abda0e2bfea22e6c6e9ec