Don't use GP to generate demo patients

Removed the global property for creating demo patients on startup.

Author: ibacher

configuration/backend_configuration/globalproperties/globalproperties-core_demo.xml

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