fix payment methods table to show proper provider name

spec/features/admin/payment_method_spec.rb

@@ -185,6 +185,16 @@ feature '
       expect(page).not_to have_content payment_method3.name
     end
 
+    it "shows only the providers of the existing payment methods" do
+      payment_method1
+      payment_method2
+      payment_method3
+
+      visit spree.admin_payment_methods_path
+
+      expect(page).to have_content "Cash/EFT/etc. (payments for which automatic validation is not required)", count: 2
+    end
+
     it "does not show duplicates of payment methods" do
       payment_method1
       payment_method2