Ignore whitespace before and after git tags

[pevik]

NOTE: Experienced on old 2.2.0, maybe it has been fixed. Also I'm not sure if it is patchwork or pwclient issue.

Space before git tags (e.g. Reviewed-by: Li Wang <liwang@redhat.com>) causes pwclient git-am to ignore them.

See:
https://lore.kernel.org/ltp/CAEemH2dU6XP+Er75eERgo+p7TyMgEjMJY7tjAGA15NOKFrZM+A@mail.gmail.com/
https://patchwork.ozlabs.org/project/ltp/patch/20251010113014.309433-1-pvorel@suse.cz/#3595268

$ cat ~/.pwclientrc
[ozlabs]
url = https://patchwork.ozlabs.org/xmlrpc/
username: ...
password: ...

$ pwclient git-am 2148087 -p ozlabs
Applying patch #2148087 using "git am"
Description: tst_cmd.h: Convert the rest of comments to kerneldoc
Applying: tst_cmd.h: Convert the rest of comments to kerneldoc

$ git log -1
commit 980c30ad8042de6694be88866a0d668aa8748bc9 (HEAD -> xxx)
Author: Petr Vorel <pvorel@suse.cz>
Date:   Fri Oct 10 13:30:14 2025 +0200

    tst_cmd.h: Convert the rest of comments to kerneldoc
    
    Move docs from the private function implementations (functions with
    trailing underscore) to functions used into functions used in the new
    API.
    
    This avoids to document private functions.
    
    Signed-off-by: Petr Vorel <pvorel@suse.cz>
    Reviewed-by: Andrea Cervesato <andrea.cervesato@suse.com>

=> There is no Reviewed-by: Li Wang <liwang@redhat.com>.