Issue 51064 - Unable to install server where IPv6 is disabled

Description:  When checking if a port is available, first attempt to
              create a socket using AF_INET6, if that fails then use
              AF_INET

relates: https://pagure.io/389-ds-base/issue/51064

Reviewed by: firstyear(Thanks!)

src/lib389/lib389/utils.py

@@ -1143,11 +1143,28 @@ def getDateTime():
 
 
 def socket_check_open(host, port):
-    with closing(socket.socket(socket.AF_INET6, socket.SOCK_STREAM)) as sock:
-        if sock.connect_ex((host, port)) == 0:
-            return True
-        else:
-            return False
+    """
+    Check if a socket can be opened.  Need to handle cases where IPv6 is completely
+    disabled.
+    """
+    try:
+        # Trying IPv6 first ...
+        family = socket.AF_INET6
+        with closing(socket.socket(family, socket.SOCK_STREAM)) as sock:
+            if sock.connect_ex((host, port)) == 0:
+                return True
+            else:
+                return False
+    except OSError:
+        # No IPv6, adjust hostname, and try IPv4 ...
+        family = socket.AF_INET
+        if host == "::1":
+            host = "127.0.0.1"
+        with closing(socket.socket(family, socket.SOCK_STREAM)) as sock:
+            if sock.connect_ex((host, port)) == 0:
+                return True
+            else:
+                return False
 
 
 def ensure_bytes(val):