phonenumber panics on parsing crafted phonenumber inputs

phonenumber is a library for parsing, formatting and validating international phone numbers. Since 0.3.4, the phonenumber parsing code may panic due to a panic-guarded out-of-bounds access on the phonenumber string. In a typical deployment of rust-phonenumber, this may get triggered by feeding a maliciously crafted phonenumber, e.g. over the network, specifically strings of the form `+dwPAA;phone-context=AA`, where the "number" part potentially parses as a number larger than 2^56. This vulnerability is fixed in 0.3.6.