Revert "Don't use GP to generate demo patients"

This reverts commit 05e89fe.

Needs more time to come up with a real solution here

Author: ibacher

configuration/backend_configuration/globalproperties/globalproperties-core_demo.xml

@@ -1,5 +1,9 @@
 <config>
     <globalProperties>
+        <globalProperty>
+            <property>referencedemodata.createDemoPatientsOnNextStartup</property>
+            <value>50</value>
+        </globalProperty>
         <!-- Queue Configuration -->
 
         <!-- https://app.openconceptlab.org/#/orgs/openmrs/sources/DemoQueueConcepts/concepts/DemoQueue-Service/ -->