[views/forms] Fix EntityFieldsForm.link_to when parent entity is being created
When the parent entity is being created and the inlined form is displayed, the
parent entity has no eid yet and `peid` is usually 'A'. So int() raises a
ValueError.
Closes #4627739.
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception