RFR: 8257707: Fix incorrect format string in Http1HeaderParser

[Turbanov Andrey]

Incorrect format string was found by IntelliJ IDEA inspection `Java | Probable bugs | Malformed format string`

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Commit messages:
 - [PATCH] Fix incorrect format string in Http1HeaderParser

Changes: https://git.openjdk.java.net/jdk/pull/1495/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1495&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257707
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1495.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1495/head:pull/1495

PR: https://git.openjdk.java.net/jdk/pull/1495