Avoid building and installing curl executable

[veloman-yunkan]

Fixes #777

We only need the libcurl library. Building and installing the curl tool leads to a build failure under Windows because of a missing strip utility.

[kelson42]

@veloman-yunkan No super happy because if I understand right, this is removed everywhere although this is a Windows only problem! Consequence will be size increase of all binaries (not only on Windows).

[veloman-yunkan]

@veloman-yunkan No super happy because if I understand right, this is removed everywhere although this is a Windows only problem! Consequence will be size increase of all binaries (not only on Windows).

Why would the size of any binary increase because of this change? This fix only tells the build system not to build the curl executable which we don't need at all.

[kelson42]

@veloman-yunkan No super happy because if I understand right, this is removed everywhere although this is a Windows only problem! Consequence will be size increase of all binaries (not only on Windows).

Why would the size of any binary increase because of this change? This fix only tells the build system not to build the curl executable which we don't need at all.

Was a fundamental misunderstanding my side.