moved a declaration to the start of block

Abiding by the C89 declaration rules so that AppVeyor build can succeed.

source/compiler/sc2.c

@@ -1344,19 +1344,18 @@ static int command(void)
           break;
         default: {
           extern char *sc_tokens[];/* forward declaration */
+          char s2[33] = "-";
           if ((char)tok == '-') {
             if (lex(&val, &str) == tNUMBER) {
               outval(-val, FALSE);
               code_idx += opargs(1);
               break;
-            } else {
-              char s2[33] = "-";
+            } else {              
               strcpy((s2 + 1), str);
               error(1, sc_tokens[tSYMBOL - tFIRST], s2);
               break;
             }/* if */
-          }/* if */
-          char s2[20];
+          }/* if */          
           if (tok<256)
             sprintf(s2,"%c",(char)tok);
           else