fix copy-and-paste error in configure's IEEE double check for sh
diff --git a/configure b/configure
index 572ea64..6c02b4a 100755
--- a/configure
+++ b/configure
@@ -428,7 +428,7 @@
# rather than using softfloat when the fpu is present but only
# supports single precision. Reject them.
printf "checking whether compiler's double type is IEEE double... "
-echo 'typedef char dblcheck[(int)sizeof(double)-5];' >> "$tmpc"
+echo 'typedef char dblcheck[(int)sizeof(double)-5];' > "$tmpc"
if $CC $CFLAGS_C99FSE $CPPFLAGS $CFLAGS -c -o /dev/null "$tmpc" >/dev/null 2>&1 ; then
printf "yes\n"
else