webkitgtk: workaround compile failure for large debug symbols

webkitgtk: workaround compile failure for large debug symbols

Originally, we move space optimize from recipe webkitgtk to
yocto-space-optimize.inc [1], it caused multiple build failures
if not include yocto-space-optimize.inc

For qemux86-64: "relocation truncated to fit: R_X86_64_32 against `.debug_info'"
For qemuarm64: "relocation truncated to fit: R_AARCH64_ABS32 against `.debug_info'"

According to the suggestion of gcc [2], pass -g1 to massively reduce the size of
the debug symbols to workaround the errors

Remove duplicate setting from yocto-space-optimize.inc at the same time.

[1] https://git.openembedded.org/openembedded-core/commit/meta?id=007c4aea10e13bd9b2d66d016c25f31c2709cbf6
[2] https://sourceware.org/bugzilla/show_bug.cgi?id=15444

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>