Add replica count 1 for single replica volume
Add replica count 1 for single replica volume

Add replica count 1 in sparse sc to create single
replica volume, needed for single node cluster

Signed-off-by: prateekpandey14 <b9840ec9e5d2558873c20ce65666d5e6288e967d@gmail.com>

yudaykiran/openebs