bsc_hack.c: Fix the -l db option (Andreas Eversberg)

Add ':' to indicate an argument will follow -l.
diff --git a/src/bsc_hack.c b/src/bsc_hack.c
index 188ccf6..deb5c57 100644
--- a/src/bsc_hack.c
+++ b/src/bsc_hack.c
@@ -1061,7 +1061,7 @@
 			{0, 0, 0, 0}
 		};
 
-		c = getopt_long(argc, argv, "hc:n:d:sar:p:f:t:C:RL:",
+		c = getopt_long(argc, argv, "hc:n:d:sar:p:f:t:C:RL:l:",
 				long_options, &option_index);
 		if (c == -1)
 			break;