resolves the hostname once and use it throughout the package

this is more efficient and fails faster on error.

patch bump

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "vban-cmd"
-version = "2.10.2"
+version = "2.10.3"
 description = "Python interface for the VBAN RT Packet Service (Sendtext)"
 authors = [{ name = "Onyx and Iris", email = "code@onyxandiris.online" }]
 license = { text = "MIT" }