The "#egg" part in source requirements isn't always handled correctly

[suutari]

When adding an URL entry with #egg part to source requirements the resulting generated requirements will contain two eggs.

E.g. following requirements.in (l:

# Following is really just a one line, but is wrapped here for readability
git+git://github.com/City-of-Helsinki/django-oidc-provider.git
@v0.5.0.post1+uc
#egg=django-oidc-provider==0.5.0.post1+uc

results in

# Following is really just a one line, but is wrapped here for readability
git+git://github.com/City-of-Helsinki/django-oidc-provider.git
@v0.5.0.post1+uc
#egg=django-oidc-provider==0.5.0.post1+uc
#egg=django-oidc-provider==0.5.0.post1+uc