DOC: lua: silence "Unexpected indentation" Sphinx warnings

When building html documentation from doc/lua-api/index.rst, sphinx
complains about some unexpected indentations:

  "doc/lua-api/index.rst:3221: WARNING: Unexpected indentation"

Silencing them without altering the original output format.
diff --git a/doc/lua-api/index.rst b/doc/lua-api/index.rst
index 038400a..63f620a 100644
--- a/doc/lua-api/index.rst
+++ b/doc/lua-api/index.rst
@@ -2955,7 +2955,7 @@
                           will only be set if it was defined elsewhere (i.e. used
                           within the configuration). For global variables (using the
                           "proc" scope), they will only be updated and never created.
-                           It is highly recommended to always set this to true.
+                          It is highly recommended to always set this to true.
 
   :see: :js:func:`AppletHTTP.unset_var`
   :see: :js:func:`AppletHTTP.get_var`
@@ -3072,7 +3072,7 @@
                           will only be set if it was defined elsewhere (i.e. used
                           within the configuration). For global variables (using the
                           "proc" scope), they will only be updated and never created.
-                           It is highly recommended to always set this to true.
+                          It is highly recommended to always set this to true.
 
   :see: :js:func:`AppletTCP.unset_var`
   :see: :js:func:`AppletTCP.get_var`
@@ -3144,6 +3144,7 @@
    comparison operators as keys followed by data type name and value pairs.
    Check out the HAProxy docs for "show table" for more details. For the
    reference, the supported operators are:
+
      "eq", "ne", "le", "lt", "ge", "gt"
 
    For large tables, execution of this function can take a long time (for