Load correct has_one association with lazy loading (#581)

spec/lazy_loading_spec.cr

@@ -14,6 +14,9 @@ describe "Lazy loading associations" do
   end
 
   it "can lazy load has_one" do
+    # to verify it is loading the correct association, not just the first
+    SignInCredentialBox.new.user_id(AdminBox.create.id).create
+
     admin = AdminBox.create
     sign_in_credential = SignInCredentialBox.new.user_id(admin.id).create
     admin.sign_in_credential!.should eq(sign_in_credential)

src/avram/associations/has_one.cr

@@ -33,10 +33,9 @@ module Avram::Associations::HasOne
       if _{{ assoc_name }}_preloaded?
         @_preloaded_{{ assoc_name }}{% unless nilable %}.not_nil!{% end %}
       elsif lazy_load_enabled? || allow_lazy
-        query = {{ model }}::BaseQuery.new
-        query.{{ foreign_key.id }}(id)
-
-        query.first{% if nilable %}?{% end %}
+        {{ model }}::BaseQuery.new
+          .{{ foreign_key.id }}(id)
+          .first{% if nilable %}?{% end %}
       else
         raise Avram::LazyLoadError.new {{ @type.name.stringify }}, {{ assoc_name.stringify }}
       end