remove impossible case

nCount == 5 is impossible; the grammar has changed since this code was written.
It used to refer to case '(' joined_table ')' range_variable op_column_commalist
which has become just '(' joined_table ')'
which thus has (by definition) no table range (alias).

Case changed in mega-(merge-)commit:

commit c41efc6d
Author: Jens-Heiner Rechtien <hr@openoffice.org>
Date:   Wed Nov 19 17:43:08 2008 +0000

    CWS-TOOLING: integrate CWS dba301a_DEV300

which seems to have done the other necessary adaptations to this code
and elsewhere.

Change-Id: I96ddbefbf34d6c155435b78aa9e5037a760232ed

connectivity/source/parse/sqlnode.cxx

@@ -2695,7 +2695,7 @@ OUString OSQLParseNode::getTableRange(const OSQLParseNode* _pTableRef)
     OSL_ENSURE(_pTableRef && _pTableRef->count() > 1 && _pTableRef->getKnownRuleID() == OSQLParseNode::table_ref,"Invalid node give, only table ref is allowed!");
     const sal_uInt32 nCount = _pTableRef->count();
     OUString sTableRange;
-    if ( nCount == 2 || (nCount == 3 && !_pTableRef->getChild(0)->isToken()) || nCount == 5 )
+    if ( nCount == 2 || (nCount == 3 && !_pTableRef->getChild(0)->isToken()) )
     {
         const OSQLParseNode* pNode = _pTableRef->getChild(nCount - (nCount == 2 ? 1 : 2));
         OSL_ENSURE(pNode && (pNode->getKnownRuleID() == OSQLParseNode::table_primary_as_range_column
@@ -2703,7 +2703,7 @@ OUString OSQLParseNode::getTableRange(const OSQLParseNode* _pTableRef)
                          ,"SQL grammar changed!");
         if ( !pNode->isLeaf() )
             sTableRange = pNode->getChild(1)->getTokenValue();
-    } // if ( nCount == 2 || nCount == 3 || nCount == 5)
+    } // if ( nCount == 2 || nCount == 3 )
 
     return sTableRange;
 }