Fix issue with multiline array interpretation for toml (#1196)

if the first line only contained a single character.

Fixes #1195

include/CLI/impl/Config_inl.hpp

@@ -414,7 +414,7 @@ inline std::vector<ConfigItem> ConfigBase::from_config(std::istream &input) cons
                     }
                 }
                 items_buffer = {item};
-            } else if(item.size() > 1 && item.front() == aStart) {
+            } else if(!item.empty() && item.front() == aStart) {
                 for(std::string multiline; item.back() != aEnd && std::getline(input, multiline);) {
                     detail::trim(multiline);
                     item += multiline;