[gnome-calculator] Try not to strip null string in gcalccmd.

[Arth Patel <arthpatel src gnome org>]

commit 92d37727245a29044f82181c481112a1b05fe610
Author: PioneerAxon <arth svnit gmail com>
Date:   Thu May 29 02:37:25 2014 +0530

    Try not to strip null string in gcalccmd.

 src/gcalccmd.vala |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/gcalccmd.vala b/src/gcalccmd.vala
index 38b4f74..6326fe9 100644
--- a/src/gcalccmd.vala
+++ b/src/gcalccmd.vala
@@ -53,7 +53,8 @@ public static int main (string[] args)
         stdout.printf ("> ");
         var line = stdin.gets (buffer);
 
-        line = line.strip ();
+        if (line != null)
+            line = line.strip ();
         if (line == null || line == "exit" || line == "quit" || line == "")
             break;