Explicitly remove non-existent parser assignment operator.
Explicitly remove non-existent parser assignment operator.

This silences MSVC

warning C4512: 'cpptoml::parser' : assignment operator could not be generated

Payshares/cpptoml,Nephatrine/cpptoml,vadz/cpptoml,skystrife/cpptoml,Nephatrine/cpptoml,vadz/cpptoml,Payshare/cpptoml,zzzworm/cpptoml,skystrife/cpptoml