Simplify the query and update qldoc

Author: luchua-bc

java/ql/src/experimental/Security/CWE/CWE-522/InsecureLdapAuth.qhelp

@@ -26,7 +26,7 @@
     </li>
     <li>
       Oracle:
-      <a href="https://docs.oracle.com/javase/tutorial/jndi/ldap/simple.html">Simple authentication consists of sending the LDAP server the fully qualified DN of the client (user) and the client's clear-text password</a>
+      <a href="https://docs.oracle.com/javase/tutorial/jndi/ldap/simple.html">Simple authentication</a>
     </li>
   </references>
 </qhelp>

java/ql/src/experimental/Security/CWE/CWE-522/InsecureLdapAuth.ql

@@ -202,13 +202,11 @@ where
   sink.getNode().asExpr() = va and
   exists(BasicAuthFlowConfig bc, DataFlow::PathNode source2, DataFlow::PathNode sink2 |
     bc.hasFlowPath(source2, sink2) and
-    source2.getNode().asExpr().(CompileTimeConstantExpr).getStringValue() = "simple" and
     sink2.getNode().asExpr() = va
   ) and
   not exists(SSLFlowConfig sc, DataFlow::PathNode source3, DataFlow::PathNode sink3 |
     sc.hasFlowPath(source3, sink3) and
-    source3.getNode().asExpr().(CompileTimeConstantExpr).getStringValue() = "ssl" and
-    sink3.getNode().asExpr() = va.getVariable().getAnAccess()
+    sink3.getNode().asExpr() = va
   )
 select sink.getNode(), source, sink, "Insecure LDAP authentication from $@.", source.getNode(),
   "LDAP connection string"