[gcalctool] Remove 'for for' in error string

[Robert Ancell <rancell src gnome org>]

commit befca8d54023c2bf3b89749588b501c17bfcd62c
Author: Robert Ancell <robert ancell gmail com>
Date:   Thu Nov 5 08:57:20 2009 +1100

    Remove 'for for' in error string

 src/mp.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/mp.c b/src/mp.c
index d539f7c..ae34a8e 100644
--- a/src/mp.c
+++ b/src/mp.c
@@ -1414,7 +1414,7 @@ mp_pwr(const MPNumber *x, const MPNumber *y, MPNumber *z)
 
     /* (-x)^y imaginary */
     if (x->sign < 0) {
-        mperr(_("The power of negative numbers only defined for for integer exponents"));
+        mperr(_("The power of negative numbers only defined for integer exponents"));
         mp_set_from_integer(0, z);
         return;
     }