[FAB-8728] Typo in peerchannel.md

There is repeating "be" in /docs/source/commands/peerchannel.md
This patch deletes one "be".

Change-Id: Ib34c908be1475c51853b5cdd67f49b3ce8c06da8
Signed-off-by: Nao Nishijima <nao.nishijima@hal.hitachi.com>
(cherry picked from commit 8e0473a)

docs/source/commands/peerchannel.md

@@ -114,7 +114,7 @@ is not performed on the peer, even though the `peer` command is used.
 To create a channel, the administrator uses the command to submit a
 configuration update transaction to the orderer. This transaction describes the
 configuration changes required to create a new channel. Moreover, this
-transaction must be be signed by the required organizations as defined by the
+transaction must be signed by the required organizations as defined by the
 current orderer configuration. Configuration transactions can be generated by
 the [`configtxgen` command](.configtxgen.html) and signed by the `peer channel signconfigtx` command.