Avoid clash between CMake build and Autotools.

Autotools expects a configuration template file at src/libssh2_config.h.in, which buildconf generates.  But the CMake build system has its CMake-specific version of the file at this path.  This means that, if you don't run buildconf, the Autotools build will fail because it configured the wrong header template.

See https://github.com/libssh2/libssh2/pull/8.

src/CMakeLists.txt

@@ -302,7 +302,7 @@ check_nonblocking_socket_support()
 set(CMAKE_REQUIRED_LIBRARIES ${SAVE_CMAKE_REQUIRED_LIBRARIES})
 
 configure_file(
-  ${CMAKE_CURRENT_SOURCE_DIR}/libssh2_config.h.in
+  ${CMAKE_CURRENT_SOURCE_DIR}/libssh2_config_cmake.h.in
   ${CMAKE_CURRENT_BINARY_DIR}/libssh2_config.h)
 # to find generated header
 target_include_directories(libssh2 PRIVATE ${CMAKE_CURRENT_BINARY_DIR})