fix for #214 (#458)

## Description, Context and related Issue
At this point it should be sufficient to test if there is at least any
measure. This integrates changes from
Max-Reger-Institut@e862266

Refs #214

## How Has This Been Tested?
See Max-Reger-Institut#3

## Types of changes
- Bug fix (non-breaking change which fixes an issue)


## Checklist

- I have performed a self-review of my code
- I have read the
[CONTRIBUTING](https://github.com/Edirom/Edirom-Online/blob/develop/CONTRIBUTING.md)
document.

add/data/xql/getInternalIdType.xql

@@ -49,9 +49,9 @@ let $internal :=
             let $measureN := functx:substring-after-last($internalId, '_')
             return (
                 if ($doc/id($mdivId)//mei:measure/@label) then
-                    $doc/id($mdivId)//mei:measure[@label eq $measureN][1]
+                    $doc/id($mdivId)//mei:measure[@label][1]
                 else
-                    $doc/id($mdivId)//mei:measure[@n eq $measureN][1]
+                    $doc/id($mdivId)//mei:measure[@n][1]
             )
         ) else
             ($internal)