Fix importFrom directive

* R/shiny-ui-base.R, NAMESPACE:
  importFrom(shiny,validate) now correct.

NAMESPACE

@@ -10,4 +10,4 @@ export(run)
 export(run_in_dir)
 export(vrfy_conf)
 import(data.table)
-importFrom("(shiny,","validate)")
+importFrom(shiny,validate)

R/shiny-ui-base.R

@@ -12,7 +12,7 @@
 ## See the License for the specific language governing permissions and
 ## limitations under the License.
 
-##' @importFrom(shiny, validate)
+##' @importFrom shiny validate
 
 react_v <- shiny::reactiveValues
 react_f <- shiny::reactive