[security-services] Errata from Section 6,SAML Extensions (cs-sstc-core-01)

Lines 1439-1444 state:

The following elements are intended specifically for use as extension points
in an extension schema; their 1439
types are set to abstract, so that the use of an xsi:type attribute with
these elements is REQUIRED: 1440
* <Assertion> 1441
* <Condition> 1442
* <Statement> 1443
* <SubjectStatement> 1444

An examination of the schema reveals that <Assertion> is of type 
<AssertionType> which is a concrete type. Thus there is no requirement
that an xsi:type attribute must be used with assertions. 

SUMMARY: Line 1441 is in error and should be removed from this list.