browser-wpadebug: Send HTTP response with HTTP/1.1 header

browser-wpadebug: Send HTTP response with HTTP/1.1 header

HTTP response was previously sent as a plaintext without the HTTP header
on port 12345. By default Android webview/Chrome assumes plaintext as
HTTP/0.9 data. Android webview/Chrome has removed support of HTTP/0.9
request/response on non-standard ports, i.e., other than port 80. This
results in error while opening URL 'http://localhost:12345/'.

Fix this by prefixing the HTTP response with the HTTP/1.1 header.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>