Do the RC4_ALIGN dance also for sideband connections.

Do the RC4_ALIGN dance also for sideband connections.

In commit 1199398 (March 2011) sc_send_bin_buffer() and
sc_recv_bin_buffer() received a fix for invalid reads/writes in
RC4(). The same fix is needed also for sc_crypt(), which was introduced
later in 2830b9f8 as part of the sideband API.

Without the fix, valgrind complains like this:

	==14435== Invalid read of size 8
	==14435==    at 0x510A03A: RC4 (in /ebio/maan/arch/Linux_x86_64/lib/libcrypto.so.0.9.8)
	==14435==    by 0x40937E: sc_crypt (crypt.c:333)
	==14435==    by 0x407233: sb_received (sideband.c:249)
	==14435==    by 0x40770F: recv_sb (client_common.c:215)
	==14435==    by 0x407FF3: client_post_select (client_common.c:427)
	==14435==    by 0x406BE8: schedule (sched.c:70)
	==14435==    by 0x404AE7: execute_client_command (client.c:115)
	==14435==    by 0x404B77: extract_matches_from_command (client.c:133)
	==14435==    by 0x404C16: generic_blob_complete (client.c:163)
	==14435==    by 0x404E13: complete_lsblob (client.c:181)
	==14435==    by 0x409AB0: create_matches (interactive.c:100)
	==14435==    by 0x409BD0: completion_generator (interactive.c:134)
	==14435==  Address 0x608bfd0 is 0 bytes inside a block of size 6 alloc'd
	==14435==    at 0x4C274A8: malloc (vg_replace_malloc.c:236)
	==14435==    by 0x405E64: para_malloc (string.c:65)
	==14435==    by 0x40935E: sc_crypt (crypt.c:330)
	==14435==    by 0x407233: sb_received (sideband.c:249)
	==14435==    by 0x40770F: recv_sb (client_common.c:215)
	==14435==    by 0x407FF3: client_post_select (client_common.c:427)
	==14435==    by 0x406BE8: schedule (sched.c:70)
	==14435==    by 0x404AE7: execute_client_command (client.c:115)
	==14435==    by 0x404B77: extract_matches_from_command (client.c:133)
	==14435==    by 0x404C16: generic_blob_complete (client.c:163)
	==14435==    by 0x404E13: complete_lsblob (client.c:181)
	==14435==    by 0x409AB0: create_matches (interactive.c:100)

See also 54cf5827.