Allow port to be left off for grm argument

Author: bridadan

src/mbed_os_tools/test/host_tests_runner/host_test_default.py

@@ -571,7 +571,15 @@ def match_log(self, line):
     @staticmethod
     def _parse_grm(grm_arg):
         grm_module, leftover = grm_arg.split(':', 1)
-        grm_host, grm_port = leftover.rsplit(':', 1)
+        parts = leftover.rsplit(':', 1)
+
+        try:
+            grm_host, grm_port = parts
+            _ = int(grm_port)
+        except ValueError:
+            # No valid port was found, so assume no port was supplied
+            grm_host = leftover
+            grm_port = None
 
         return {
             "grm_module" : grm_module,

src/mbed_os_tools/test/mbed_test_api.py

@@ -571,7 +571,16 @@ def parse_global_resource_mgr(global_resource_mgr):
     """
     try:
         platform_name, module_name, leftover = global_resource_mgr.split(':', 2)
-        ip_name, port_name = leftover.rsplit(':', 1)
+        parts = leftover.rsplit(':', 1)
+
+        try:
+            ip_name, port_name = parts
+            _ = int(port_name)
+        except ValueError:
+            # No valid port was found, so assume no port was supplied
+            ip_name = leftover
+            port_name = None
+
     except ValueError as e:
         return False
     return platform_name, module_name, ip_name, port_name