RegularExpression: Fix regression in 'find' method

Fix a return value accidentally changed by commit cff58f07
(RegularExpression: New RegularExpressionMatch class, 2017-12-04).

RegularExpression.cxx

@@ -901,7 +901,7 @@ bool RegularExpression::find(char const* string,
     // We know what char it must start with.
     while ((s = strchr(s, this->regstart)) != 0) {
       if (regFind.regtry(s, rmatch.startp, rmatch.endp, this->program))
-        return false;
+        return true;
       s++;
     }
   else