toolchain/wrapper: add missing qstrip to info.mk export

toolchain/wrapper: add missing qstrip to info.mk export

When using an external toolchain, the SetToolchainInfo function
is missing a qstrip call on GCC_VERSION, which results in quotes
making it to the toolchain info.mk file.

This leads to a failure to build the libgcc ipk package because
the quotes make it to its version and filename. For some reason,
it only fails on the first make invocation, but succeeds on
subsequent ones on my setup.

Fix this issue by adding the qstrip, making it consistent with
the internal toolchain approach.

Signed-off-by: Ondrej Cierny <o.cierny@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/19192
Signed-off-by: Robert Marko <robimarko@gmail.com>