package/linux-headers: fix whitespace error in Config.in.host

The cherry-pick from master introduced a space-before-tab error. This is
reported by check-package.

Fixes: https://gitlab.com/buildroot.org/buildroot/-/jobs/287919259

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/linux-headers/Config.in.host

@@ -291,7 +291,7 @@ config BR2_DEFAULT_KERNEL_HEADERS
 	default "4.9.190"	if BR2_KERNEL_HEADERS_4_9
 	default "4.14.141"	if BR2_KERNEL_HEADERS_4_14
 	default "4.19.69"	if BR2_KERNEL_HEADERS_4_19
- 	default "4.20.17"	if BR2_KERNEL_HEADERS_4_20
+	default "4.20.17"	if BR2_KERNEL_HEADERS_4_20
 	default BR2_DEFAULT_KERNEL_VERSION if BR2_KERNEL_HEADERS_VERSION
 	default "custom"	if BR2_KERNEL_HEADERS_CUSTOM_TARBALL
 	default BR2_KERNEL_HEADERS_CUSTOM_REPO_VERSION \