Issue #19744: Handle missing SSL/TLS in ensurepip

- now also allows POSIX installation with SSL/TLS missing
- a goal for pip 1.6 is to allow local use without SSL/TLS
diff --git a/Lib/ensurepip/__init__.py b/Lib/ensurepip/__init__.py
index e8d6abe..3f4e449 100644
--- a/Lib/ensurepip/__init__.py
+++ b/Lib/ensurepip/__init__.py
@@ -144,6 +144,11 @@
 
 
 def _main(argv=None):
+    if ssl is None:
+        print("Ignoring ensurepip failure: {}".format(_MISSING_SSL_MESSAGE),
+              file=sys.stderr)
+        return
+
     import argparse
     parser = argparse.ArgumentParser(prog="python -m ensurepip")
     parser.add_argument(