Fix incorrect timestamp in region file header recalculation (#11318)

patches/server/Attempt-to-recalculate-regionfile-header-if-it-is-co.patch

@@ -411,7 +411,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +            // simply destroy the timestamp header, it's not used
 +
 +            for (int i = 0; i < 32 * 32; ++i) {
-+                this.timestamps.put(i, calculatedOffsets[i] != 0 ? (int)System.currentTimeMillis() : 0); // write a valid timestamp for valid chunks, I do not want to find out whatever dumb program actually checks this
++                this.timestamps.put(i, calculatedOffsets[i] != 0 ? RegionFile.getTimestamp() : 0); // write a valid timestamp for valid chunks, I do not want to find out whatever dumb program actually checks this
 +            }
 +
 +            // write new header