[FAB-6010] fixed the wrong URL in examples/README

As the FAB-6010 pointed out, there are two URL links containing "fabric/example/..." which should be "fabric/examples/..." instead. This patch fixed them. In adtion, it is confirmed that no other documentation contain the same URL error.

Change-Id: If02b9338297219ae35c8be99dbfab402eaa91a77
Signed-off-by: luomin <luomin_tokyotech@hotmail.com>

Author: luomin

examples/configtxupdate/README.md

@@ -81,7 +81,7 @@ CGO_CFLAGS=" " GOBIN=/home/yellickj/go/src/github.com/hyperledger/fabric/build/b
 Binary available as build/bin/configtxgen
 ```
 
-It is recommended to run the example by invoking the script `fabric/example/configtxupdate/bootstrap_batchsize/script.sh` as follows:
+It is recommended to run the example by invoking the script `fabric/examples/configtxupdate/bootstrap_batchsize/script.sh` as follows:
 
 ```
 INTERACTIVE=true ./script.sh
@@ -160,7 +160,7 @@ ORDERER_GENERAL_LOGLEVEL=debug orderer
 
 Reconfiguring a channel can be performed in a very similar way to modifying a genesis config.
 
-The recommended path to proceed with this example is to run the script located at `fabric/example/configtxupdate/reconfigure_batchsize/script.sh` by invoking
+The recommended path to proceed with this example is to run the script located at `fabric/examples/configtxupdate/reconfigure_batchsize/script.sh` by invoking
 
 ```
 INTERACTIVE=true ./script.sh