Handle sysctl.conf files that use ';' for comments (#20576)

'#' and ';' are both valid comment chars for sysctl.conf files
according to the 'man sysctl.conf':

  "Lines which begin with a # or ; are considered comments and ignored."

Fixes #20569

lib/ansible/modules/system/sysctl.py

@@ -307,7 +307,7 @@ class SysctlModule(object):
             self.file_lines.append(line)
 
             # don't split empty lines or comments
-            if not line or line.startswith("#"):
+            if not line or line.startswith(("#", ";")):
                 continue
 
             k, v = line.split('=',1)
@@ -320,7 +320,7 @@ class SysctlModule(object):
         checked = []
         self.fixed_lines = []
         for line in self.file_lines:
-            if not line.strip() or line.strip().startswith("#"):
+            if not line.strip() or line.strip().startswith(("#", ";")):
                 self.fixed_lines.append(line)
                 continue
             tmpline = line.strip()