Fix semicolon printing when restricting max line length

Fixes #755

lib/output.js

@@ -161,6 +161,8 @@ function OutputStream(options) {
         str = String(str);
         var ch = str.charAt(0);
         if (might_need_semicolon) {
+            might_need_semicolon = false;
+
             if ((!ch || ";}".indexOf(ch) < 0) && !/[;]$/.test(last)) {
                 if (options.semicolons || requireSemicolonChars(ch)) {
                     OUTPUT += ";";
@@ -171,11 +173,14 @@ function OutputStream(options) {
                     current_pos++;
                     current_line++;
                     current_col = 0;
+
+                    // reset the semicolon flag, since we didn't print one now and
+                    // might still have to later
+                    might_need_semicolon = true;
                 }
                 if (!options.beautify)
                     might_need_space = false;
             }
-            might_need_semicolon = false;
         }
 
         if (!options.beautify && options.preserve_line && stack[stack.length - 1]) {