Tests: fixed loading selected module version.

Previously, for PHP, Ruby, and Perl the latest version was always loaded
in multi-version tests.

test/unit/applications/lang/perl.py

@@ -7,13 +7,17 @@ class TestApplicationPerl(TestApplicationProto):
 
     def load(self, script, name='psgi.pl', **kwargs):
         script_path = option.test_dir + '/perl/' + script
+        appication_type = self.get_appication_type()
+
+        if appication_type is None:
+            appication_type = self.application_type
 
         self._load_conf(
             {
                 "listeners": {"*:7080": {"pass": "applications/" + script}},
                 "applications": {
                     script: {
-                        "type": self.application_type,
+                        "type": appication_type,
                         "processes": {"spare": 0},
                         "working_directory": script_path,
                         "script": script_path + '/' + name,