Fix bad handling of interpolated variables in the Groovy mode

FIX: Fix an issue in the Groovy mode where himBHsinterpolated variable style would
continue after whitespace.

Issue codemirror/codemirror5#7103

mode/groovy.js

@@ -115,10 +115,8 @@ function tokenBaseUntilBrace() {
 
 function tokenVariableDeref(stream, state) {
   var next = stream.match(/^(\.|[\w\$_]+)/)
-  if (!next) {
-    state.tokenize.pop()
-    return state.tokenize[state.tokenize.length-1](stream, state)
-  }
+  if (!next || !stream.match(next[0] == "." ? /^[\w$_]/ : /^\./)) state.tokenize.pop()
+  if (!next) return state.tokenize[state.tokenize.length-1](stream, state)
   return next[0] == "." ? null : "variable"
 }