[FIX] payment_*: remove obsolete license entry

The license entry in the manifest files for these modules were
leftovers from previous versions.

Once integrated in Odoo Community they share the same license as all
other modules, as mentioned in the LICENSE notice at the top of the
files.

opw-743686

addons/payment_payumoney/__manifest__.py

@@ -16,5 +16,4 @@
         'views/payment_payumoney_templates.xml',
         'data/payment_acquirer_data.xml',
     ],
-    'license': 'OEEL-1',
 }

addons/payment_stripe/__manifest__.py

@@ -14,5 +14,4 @@
     ],
     'images': ['static/description/icon.png'],
     'installable': True,
-    'license': 'OEEL-1',
 }