Rename diff.suppress-blank-empty to diff.suppressBlankEmpty

All the other config variables use CamelCase.  This config variable should
not be an exception.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/diff.c b/diff.c
index 0484601..5b85b40 100644
--- a/diff.c
+++ b/diff.c
@@ -118,7 +118,9 @@
 	}
 
 	/* like GNU diff's --suppress-blank-empty option  */
-	if (!strcmp(var, "diff.suppress-blank-empty")) {
+	if (!strcmp(var, "diff.suppressblankempty") ||
+			/* for backwards compatibility */
+			!strcmp(var, "diff.suppress-blank-empty")) {
 		diff_suppress_blank_empty = git_config_bool(var, value);
 		return 0;
 	}