fix(system_python): Remove printing of not always present attribute (#3781)

This attribute is not part of the Python public API and in Debian 10
Buster (OpenJDK 11, gcc 8.3.0) it seems to not be defined.

This reverts one of the debug logging statements added in
https://github.com/bazel-contrib/rules_python/pull/3667

Fixes #3774

---------

Co-authored-by: Ignas Anikevicius <240938+aignas@users.noreply.github.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1342e2f..3916f19 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -84,6 +84,9 @@
 * (pypi) Fix `importlib.metadata.files` by ensuring `RECORD` is included in
   installed wheel targets, except when built from sdist
   ([#3024](https://github.com/bazel-contrib/rules_python/issues/3024)).
+* (system_python) Fix AttributeError exception on Debian 10 Buster
+  python installations which may not set `sys._base_executable`
+  ([#3774](https://github.com/bazel-contrib/rules_python/issues/3774)).
 * (windows) Fix `py_test`/`py_binary` failure when the target name contains
   path separators; the bootstrap stub is now declared as a sibling of the
   `.exe` launcher
@@ -92,7 +95,6 @@
   towards the underlying `*.update` target.
   ([#3787](https://github.com/bazel-contrib/rules_python/pull/3787))
 
-
 {#v0-0-0-added}
 ### Added
 * (toolchain) Added {obj}`python.override.toolchain_target_settings` to allow
diff --git a/python/private/python_bootstrap_template.txt b/python/private/python_bootstrap_template.txt
index 0d28aff..38c93ec 100644
--- a/python/private/python_bootstrap_template.txt
+++ b/python/private/python_bootstrap_template.txt
@@ -568,7 +568,7 @@
   print_verbose("VENV_REL_SITE_PACKAGES:", VENV_REL_SITE_PACKAGES)
   print_verbose("WORKSPACE_NAME:", WORKSPACE_NAME )
   print_verbose("bootstrap sys.executable:", sys.executable)
-  print_verbose("bootstrap sys._base_executable:", sys._base_executable)
+  print_verbose("bootstrap sys._base_executable:", getattr(sys, "_base_executable", "unknown"))
   print_verbose("bootstrap sys.version:", sys.version)
 
   args = sys.argv[1:]