[#3524] add stamp-h* to gitignore

Under some unknown conditions, you can get `stamp-h2`, and it probably
keeps incrementing.

Author: andrei-pavel

.gitignore

@@ -34,7 +34,7 @@ config.h.in~
 /ltmain.sh
 /missing
 /py-compile
-/stamp-h1
+/stamp-h*
 /test-driver
 /ylwrap
 /kea_version.h