Inconsistent default values for RequestConfig.protocolUpgradeEnabled

[jan luehe]

 Support for org.apache.hc.client5.http.config.RequestConfig's 
"protocolUpgradeEnabled" was introduced via this commit:  
https://github.com/apache/httpcomponents-client/commit/3235f009d5673536be5c668df409ac3f83808d89
The default RequestConfig constructor sets it to "false", whereas the 
RequestConfig$Builder sets it to "true" by default.
Same is true for RequestConfig's "contentCompressionEnabled" and 
"hardCancellationEnabled" fields.
I believe RequestConfig$Builder should initialize these fields to "false" also.