Resolving Issue #40 - when using php with all error output or using a code analyzer, the http_response_header variable looks as though it won't be initialized before being used. Initializing it to null to alleviate the emitted warning.
Resolving Issue #40 - when using php with all error output or using a code analyzer, the http_response_header variable looks as though it won't be initialized before being used. Initializing it to null to alleviate the emitted warning.

pankajit/solr-php-client,hacioguz/solr-php-client,renjithkathirolil/solr-php-client,SakuraZhang/solr-php-client,napoler/solr-php-client,AndBicScadMedia/solr-php-client,pankajit/solr-php-client,SakuraZhang/solr-php-client,AndBicScadMedia/solr-php-client,napoler/solr-php-client,hacioguz/solr-php-client