Update themes/mairan/mairan.theme.bash

Co-authored-by: Koichi Murase <[email protected]>

Author: seefood

themes/mairan/mairan.theme.bash

@@ -60,7 +60,7 @@ PS3=">> "
 __my_rvm_ruby_version() {
 	local version gemset
 	gemset=$(echo "${GEM_HOME}" | awk -F'@' '{print $2}')
-	[[ "${gemset}" != "" ]] && gemset="@${gemset}"
+	[[ -n "${gemset}" ]] && gemset="@${gemset}"
 	local version
 	version=$(echo "${MY_RUBY_HOME}" | awk -F'-' '{print $2}')
 	local full="${version}${gemset}"