[BUILD] Disable MSCCLPP build by default (#1283)

Signed-off-by: nileshnegi <Nilesh.Negi@amd.com>

install.sh

@@ -24,7 +24,7 @@ install_dependencies=false
 install_library=false
 install_prefix="${ROCM_PATH}"
 msccl_kernel_enabled=true
-mscclpp_enabled=true
+mscclpp_enabled=false
 num_parallel_jobs=$(nproc)
 npkit_enabled=false
 openmp_test_enabled=false