test-minirst: don't test on invalid reST input

Input such as

      Only the
    left-most line
  (this line!)
    is significant
      for the indentation

is not valid reStructuredText: the first line starts a block quote,
but then the second line is not allowed to be unindented.

tests/test-minirst.py

@@ -12,28 +12,13 b' def debugformat(title, text, width):'
 paragraphs = """
 This is some text in the first paragraph.
 
-  An indented paragraph
-  with just two lines.
-
-
-The third paragraph. It is followed by some
-random lines with spurious spaces.
+  A small indented paragraph.
+  It is followed by some lines
+  containing random whitespace.
  
   
    
-  
- 
-No indention
- here, despite
-the uneven left
- margin.
-
-      Only the
-    left-most line
-  (this line!)
-    is significant
-      for the indentation
-
+The third and final paragraph.
 """
 
 debugformat('paragraphs', paragraphs, 60)

tests/test-minirst.py.out

@@ -2,15 +2,10 b' paragraphs formatted to fit within 60 ch'
 ----------------------------------------------------------------------
 This is some text in the first paragraph.
 
-  An indented paragraph with just two lines.
-
-The third paragraph. It is followed by some random lines
-with spurious spaces.
+  A small indented paragraph. It is followed by some lines
+  containing random whitespace.
 
-No indention here, despite the uneven left margin.
-
-  Only the left-most line (this line!) is significant for
-  the indentation
+The third and final paragraph.
 ----------------------------------------------------------------------
 
 paragraphs formatted to fit within 30 characters:
@@ -18,19 +13,12 b' paragraphs formatted to fit within 30 ch'
 This is some text in the first
 paragraph.
 
-  An indented paragraph with
-  just two lines.
-
-The third paragraph. It is
-followed by some random lines
-with spurious spaces.
+  A small indented paragraph.
+  It is followed by some lines
+  containing random
+  whitespace.
 
-No indention here, despite the
-uneven left margin.
-
-  Only the left-most line
-  (this line!) is significant
-  for the indentation
+The third and final paragraph.
 ----------------------------------------------------------------------
 
 definitions formatted to fit within 60 characters: