Enable shared cache on the server demonstration. (CVS 2899)

FossilOrigin-Name: 8719f880a395db8be65ea45615d8e55985306f1e

src/server.c

@@ -331,6 +331,7 @@ int sqlite3_client_close(sqlite3 *pDb){
 ** true.
 */
 void *sqlite3_server(void *NotUsed){
+  sqlite3_enable_shared_cache(1);
   if( pthread_mutex_trylock(&g.serverMutex) ){
     return 0;  /* Another server is already running */
   }