fix: use hasOwnProperty instead of []

`keywordsBlockAndTransactionProperties[cur].some` is not a function error.

If current token (`cur`) is a method from Object like `toString`, `keywordsBlockAndTransactionProperties[cur]` is
keywordsBlockAndTransactionProperties['toString'] and would be a function, then `fn.some` would throw the error.

Author: Yukaii

mode/solidity/solidity.js

@@ -339,17 +339,17 @@ CodeMirror.defineMode('solidity', function(config) {
 
     if (
       keywordsMoreBlockAndTransactionProperties.propertyIsEnumerable(cur) ||
-      (keywordsBlockAndTransactionProperties[cur] &&
-        keywordsBlockAndTransactionProperties[cur].some(function(item) {
+      (keywordsBlockAndTransactionProperties.hasOwnProperty(cur) &&
+        keywordsBlockAndTransactionProperties[cur].some(function (item) {
           return stream.match('.' + item)
         }))
     ) {
       return 'variable-2'
     }
 
     if (
-      keywordsAbiEncodeDecodeFunctions[cur] &&
-      keywordsAbiEncodeDecodeFunctions[cur].some(function(item) {
+      keywordsAbiEncodeDecodeFunctions.hasOwnProperty(cur) &&
+      keywordsAbiEncodeDecodeFunctions[cur].some(function (item) {
         return stream.match('.' + item)
       })
     ) {