Removed disk instance from the StorageClassLsItem

eos_cta/protobuf/cta_admin.proto

@@ -431,13 +431,12 @@ message ShowQueuesItem {
 }
 
 message StorageClassLsItem {
-  string disk_instance                      = 1;
-  string name                               = 2;
-  uint64 nb_copies                          = 3;
-  string vo                                 = 4;
-  cta.common.EntryLog creation_log          = 5;
-  cta.common.EntryLog last_modification_log = 6;
-  string comment                            = 7;
+  string name                               = 1;
+  uint64 nb_copies                          = 2;
+  string vo                                 = 3;
+  cta.common.EntryLog creation_log          = 4;
+  cta.common.EntryLog last_modification_log = 5;
+  string comment                            = 6;
 }
 
 message TapeLsItem {