Revert "script option: fix IndentationError with buildout 2, if some lines are indented."

This reverts the following commits partially:
  d157d8a1
  e92d31cf

With buildout 2, indentation is either fully removed (if anything
starts on the same line as '<option-name> =') or preverved (the same
number of leading spaces if stripped). Any use that required these
commits was a misuse. They could even break valid Python.

slapos/recipe/build/__init__.py

@@ -28,7 +28,6 @@ import errno
 import logging
 import os
 from platform import uname
-import re
 import setuptools
 import shlex
 import shutil
@@ -275,9 +274,6 @@ class Script(EnvironMixin):
     if self.script:
       if self.options.get('format', 'yes') in TRUE_LIST:
         self.script = self.script % self.options
-      if re.match(r'^[ \t]', self.script):
-        # Buildout 2 keeps all indentation unless all lines have the same indentation.
-        self.script = 'if True:\n' + self.script
     if self.options.get('keep-on-error', '').strip().lower() in TRUE_LIST:
       self.logger.debug('Keeping directories in case of errors')
       self.keep_on_error = True