[pgAdmin4][Patch] Minor fix in test file for the Template loader

Hi,

PFA patch to fix the issue in test suite for template loader.

*Issue(Python3):*
murtuza(at)vm:~/pgadmin4/web/regression$ python3 runtests.py
pgAdmin 4 - Application Initialisation
======================================

The configuration database - '/../.pgadmin/test_pgadmin4.db' does not exist.
Entering initial setup mode...
NOTE: Configuring authentication for SERVER mode.

The configuration database has been created at /../.pgadmin/test_pgadmin4.db
Traceback (most recent call last):
File "runtests.py", line 250, in <module>
test_module_list = get_test_modules(args)
File "runtests.py", line 138, in get_test_modules
TestsGeneratorRegistry.load_generators('pgadmin')
File "../../pgadmin4/web/pgadmin/utils/route.py", line 66, in
load_generators
import_module(module_name)
File "/../../3.5/lib/python3.5/importlib/__init__.py", line 126, in
import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 986, in _gcd_import
File "<frozen importlib._bootstrap>", line 969, in _find_and_load
File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 658, in exec_module
File "<frozen importlib._bootstrap_external>", line 764, in get_code
File "<frozen importlib._bootstrap_external>", line 724, in source_to_code
File "<frozen importlib._bootstrap>", line 222, in
_call_with_frames_removed
File
"/../../pgadmin4/web/pgadmin/utils/tests/test_versioned_template_loader.py",
line 50
except TemplateNotFound, e:
^
SyntaxError: invalid syntax

--
Regards,
Murtuza Zabuawala
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company