Fixes a bug introduced by commit [4895a4]

Re-enables R with .model like
.model R_NOISELESS RES (TCE=0 T_ABS=-273.15)
R77 1 0 R_NOISELESS 100

src/frontend/inpcom.c

@@ -4276,6 +4276,8 @@ int get_number_terminals(char *c)
         case 'b':
         case 'v':
         case 'i':
+            return 2;
+            break;
         case 'd':
             i = 0;
             /* find the first token with "off" or "=" in the line*/