Fix #959 (typo in cosmocc --version)

Author: mrdomino

tool/cosmocc/bin/cosmocc

@@ -15,7 +15,7 @@ $PROG (GCC) $GCC_VERSION
 Copyright (c) 2024 Justine Alexandra Roberts Tunney
 Cosmopolitan Libc and LLVM libcxx/compiler-rt are subject to non-GPL
 notice licenses, e.g. ISC, MIT, etc. Your compiled programs must embed
-our copyright notices. This toolchain is configured to do so default.
+our copyright notices. This toolchain is configured to do so by default.
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 For more information, see the Cosmopolitan LICENSE files.
 Copyright (C) 2022 Free Software Foundation, Inc.