Fix syntax error in CheckovLinter.py

Fix syntax error in CheckovLinter.py by adding missing colon.

Author: bdovaz

megalinter/linters/CheckovLinter.py

@@ -82,7 +82,7 @@ def build_lint_command(self, file=None) -> list:
                 self.cli_lint_extra_args_after.append("--file")
                 self.cli_lint_extra_args_after += diff_files
 
-            if len(diff_files) > 0
+            if len(diff_files) > 0:
                 self.self.cli_lint_mode_project_extra_args_after.remove("--directory")
                 self.self.cli_lint_mode_project_extra_args_after.remove(".")