Fix specs failing after Money 6.18.0 release

The release includes RubyMoney/money#1026
which replaces the html entity for EURO with its symbol.

(cherry picked from commit 2b88945)

core/spec/lib/spree/money_spec.rb

@@ -148,13 +148,13 @@
     it "formats as HTML if asked (nicely) to" do
       money = Spree::Money.new(10, format: '%n %u')
       # The HTML'ified version of "10.00 €"
-      expect(money.to_html).to eq("<span class=\"money-whole\">10</span><span class=\"money-decimal-mark\">.</span><span class=\"money-decimal\">00</span> <span class=\"money-currency-symbol\">&#x20AC;</span>")
+      expect(money.to_html).to eq("<span class=\"money-whole\">10</span><span class=\"money-decimal-mark\">.</span><span class=\"money-decimal\">00</span> <span class=\"money-currency-symbol\">€</span>")
     end
 
     it "formats as HTML with currency" do
       money = Spree::Money.new(10, format: '%n %u', with_currency: true)
       # The HTML'ified version of "10.00 €"
-      expect(money.to_html).to eq("<span class=\"money-whole\">10</span><span class=\"money-decimal-mark\">.</span><span class=\"money-decimal\">00</span> <span class=\"money-currency-symbol\">&#x20AC;</span> <span class=\"money-currency\">EUR</span>")
+      expect(money.to_html).to eq("<span class=\"money-whole\">10</span><span class=\"money-decimal-mark\">.</span><span class=\"money-decimal\">00</span> <span class=\"money-currency-symbol\">€</span> <span class=\"money-currency\">EUR</span>")
     end
   end