fix GitRepository#getFirstRevision()

--max-count is applied before --reverse

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/history/GitRepository.java

@@ -389,7 +389,6 @@ private String getFirstRevision(String fullpath) throws IOException {
                 ensureCommand(CMD_PROPERTY_KEY, CMD_FALLBACK),
                 "rev-list",
                 "--reverse",
-                "--max-count=1",
                 "HEAD",
                 "--",
                 fullpath