Fix encoding problem from curl repostory on github

Pushing curl repository to gerrit fails with a message:
remote: error: internal error while processing changes
java.nio.charset.IllegalCharsetNameException: 'utf8'

curl repository url: https://github.com/bagder/curl.git

To avoid this problem encodingAliases in RawParseUtils have
been extended to contain "'utf8'" (single quoted utf8) string.

Change-Id: I40f613cfdcabf0dc9455bee45116ab8d8c7dd6ee
Signed-off-by: Eryk Szymanski <eryksz@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/util/RawParseUtils.java

@@ -83,6 +83,7 @@ public final class RawParseUtils {
 	static {
 		encodingAliases = new HashMap<String, Charset>();
 		encodingAliases.put("latin-1", Charset.forName("ISO-8859-1")); //$NON-NLS-1$ //$NON-NLS-2$
+		encodingAliases.put("'utf8'", Charset.forName("UTF-8")); //$NON-NLS-1$ //$NON-NLS-2$
 
 		digits10 = new byte['9' + 1];
 		Arrays.fill(digits10, (byte) -1);