Fix bug in GenerateSignature that calculates invalid signature base string if URL includes an encoded value such as %20. The encoded value ended up being double encoded in the signature base string as %2520.
Fix bug in GenerateSignature that calculates invalid signature base string if URL includes an encoded value such as %20. The encoded value ended up being double encoded in the signature base string as %2520.

andyfmiller/LtiLibrary,easygenerator/LtiLibrary