remove buildtime from generated files

Each rebuild gets a different file even if the sources are unchanged.
Debian sells this as "reproducible build".
SUSE just wants to avoid needless republish of otherwise identical binaries.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

tools/keymap-gen

diff --git a/tools/keymap-gen b/tools/keymap-gen
index cd5a391..7965d37 100755
--- a/tools/keymap-gen
+++ b/tools/keymap-gen
@@ -317,9 +317,8 @@
         raise NotImplementedError()
 
     def generate_header(self, database, args):
-        today = time.strftime("%Y-%m-%d %H:%M")
         self._boilerplate([
-            "This file is auto-generated from keymaps.csv on %s" % today,
+            "This file is auto-generated from keymaps.csv",
             "Database checksum sha256(%s)" % database.mapchecksum,
             "To re-generate, run:",
             "  %s" % args,