Bug: The header field name is case-insensitive but is not processed as such.

[yunjova]

There is a bug in the file: "Sming/Sming/SmingCore/Network/HttpRequest.cpp".

The header field name is case-insensitive according to:
https://tools.ietf.org/html/rfc7230
...
3.2. Header Fields
Each header field consists of a case-insensitive field name followed
by a colon (":"), optional leading whitespace, the field value, and
optional trailing whitespace.
...

So in: "Sming/Sming/SmingCore/Network/HttpRequest.cpp"
the function:
String HttpRequest::getHeader(String headerName, String defaultValue /* = "" */)
must do a case-insensitive compare.

Example: It should accept Content-Type: but also Content-type: (lowercase t in -type).

[patrickjahns]

Good catch. The proposed solution is not complete. There are more parts of the code that need to be addressed in order to enable case insensitive parsing and processing

I will provide a patch towards #622 and #631

[patrickjahns]

Fix provided - please see #681 and test it