Don't generate errors when searching customer user

Kernel/System/CustomerUser.pm

@@ -188,6 +188,19 @@ sub CustomerSearch {
     my $DynamicFieldBackendObject = $Kernel::OM->Get('Kernel::System::DynamicField::Backend');
 
     my %Data;
+
+    # Return empty set if no search parameter is defined.
+    if (
+        !$Param{Search}
+        && !$Param{UserLogin}
+        && !$Param{PostMasterSearch}
+        && !$Param{CustomerID}
+        && !$Param{CustomerIDRaw}
+        )
+    {
+        return %Data;
+    }
+
     SOURCE:
     for my $Count ( '', 1 .. 10 ) {
 

Kernel/System/CustomerUser/LDAP.pm

@@ -377,7 +377,7 @@ sub CustomerSearch {
     {
         $Kernel::OM->Get('Kernel::System::Log')->Log(
             Priority => 'error',
-            Message  => 'Need Search, UserLogin, PostMasterSearch or CustomerID!'
+            Message  => 'Need Search, UserLogin, PostMasterSearch, CustomerIDRaw or CustomerID!'
         );
         return;
     }