bumped github image version in source_specs.yaml file

Author: midavadim

airbyte-config/init/src/main/resources/seed/source_specs.yaml

@@ -2156,7 +2156,7 @@
     supportsNormalization: false
     supportsDBT: false
     supported_destination_sync_modes: []
-- dockerImage: "airbyte/source-github:0.2.18"
+- dockerImage: "airbyte/source-github:0.2.19"
   spec:
     documentationUrl: "https://docs.airbyte.io/integrations/sources/github"
     connectionSpecification: