fix: Remove "Material Issue" purpose from pick list

- Because in material issue we already define source warehouse
diff --git a/erpnext/stock/doctype/material_request/material_request.js b/erpnext/stock/doctype/material_request/material_request.js
index feaa413..1027dd5 100644
--- a/erpnext/stock/doctype/material_request/material_request.js
+++ b/erpnext/stock/doctype/material_request/material_request.js
@@ -67,7 +67,6 @@
 				}
 
 				if (frm.doc.material_request_type === "Material Issue") {
-					add_create_pick_list_button();
 					frm.add_custom_button(__("Issue Material"),
 						() => frm.events.make_stock_entry(frm), __('Create'));
 				}
diff --git a/erpnext/stock/doctype/pick_list/pick_list.json b/erpnext/stock/doctype/pick_list/pick_list.json
index dbfd7d1..c7aa458 100644
--- a/erpnext/stock/doctype/pick_list/pick_list.json
+++ b/erpnext/stock/doctype/pick_list/pick_list.json
@@ -98,7 +98,7 @@
    "fieldname": "purpose",
    "fieldtype": "Select",
    "label": "Purpose",
-   "options": "Material Transfer for Manufacture\nMaterial Issue\nMaterial Transfer\nDelivery against Sales Order"
+   "options": "Material Transfer for Manufacture\nMaterial Transfer\nDelivery against Sales Order"
   },
   {
    "depends_on": "eval:['Material Transfer', 'Material Issue'].includes(doc.purpose)",
@@ -115,7 +115,7 @@
   }
  ],
  "is_submittable": 1,
- "modified": "2019-08-26 06:52:04.532885",
+ "modified": "2019-08-26 16:11:03.184637",
  "modified_by": "Administrator",
  "module": "Stock",
  "name": "Pick List",
diff --git a/erpnext/stock/doctype/pick_list/pick_list.py b/erpnext/stock/doctype/pick_list/pick_list.py
index 16bb9e6..d5bf643 100644
--- a/erpnext/stock/doctype/pick_list/pick_list.py
+++ b/erpnext/stock/doctype/pick_list/pick_list.py
@@ -359,9 +359,14 @@
 
 def update_stock_entry_based_on_material_request(pick_list, stock_entry):
 	for location in pick_list.locations:
+		target_warehouse = None
+		if location.material_request_item:
+			target_warehouse = frappe.get_value('Material Request Item',
+				location.material_request_item, 'warehouse')
 		item = frappe._dict()
 		item.item_code = location.item_code
 		item.s_warehouse = location.warehouse
+		item.t_warehouse = target_warehouse
 		item.qty = location.qty
 		item.transfer_qty = location.stock_qty
 		item.uom = location.uom