activated the test

library/src/test/java/org/mustangproject/ZUGFeRD/ZF2ZInvoiceImporterTest.java

@@ -416,7 +416,7 @@ this would test if for all elements/attributes
 				/*
 				<cbc:Name>Seller contact point</cbc:Name>
         <cbc:Telephone>+41 345 654455</cbc:Telephone>
-        <cbc:ElectronicMail>seller@contact.de);*
+        <cbc:ElectronicMail>seller@contact.de);*/
 		} catch (XPathExpressionException | ParseException e) {
 			hasExceptions = true;
 		} catch (JsonProcessingException e) {
@@ -428,6 +428,6 @@ this would test if for all elements/attributes
 		assertEquals(new BigDecimal("205.00"), tc.getGrandTotal());
 
 	}
-*/
+
 
 }