correct the handling of a minus character a in a space delimited parameter list. fix #68

Author: Horcrux7

src/com/inet/lib/less/LessParser.java

@@ -764,7 +764,7 @@ private Expression parseExpression( char leftOperator ) {
                                     left = concat( left, ' ', buildExpression( trim( builder ) ) );
                                 }
                                 builder.append( ch );
-                                builder.append( ch2 );
+                                back( ch2 );
                                 wasWhite = false;
                                 break;
                              } else {

test/com/inet/lib/less/samples/general/minus.css

@@ -27,6 +27,7 @@
   calcVariable: calc(90% -10px);
   calcNested: calc(100% - (2 * 2em));
   calcEscaped: calc(100% - (2 * 2em));
+  margin: 0 -12;
 }
 :root {
   --main-bg-color: pink;

test/com/inet/lib/less/samples/general/minus.less

@@ -31,6 +31,7 @@
   calcVariable: calc(@a -@b);
   calcNested: calc(100% - (2 * 2em));
   calcEscaped: calc(~"100% - (2 * 2em)");
+  margin: 0 -((@line-height-computed / 2) + 30);
 }
 :root {
   --main-bg-color: pink;