Fix for echo newline suppression detection

Submitted by: Keith Parks

src/configure

@@ -919,7 +919,7 @@ if test "$ECHO_N_OUT" -eq 0; then
 else
   if test "ECHO_C_OUT" -eq 0; then
     DASH_N=
-    BACKSLASH_C= '\\\\c'
+    BACKSLASH_C='\\\\c'
   else
     { echo "configure: error: "echo behaviour undetermined"" 1>&2; exit 1; }
   fi

src/configure.in

@@ -82,7 +82,7 @@ if test "$ECHO_N_OUT" -eq 0; then
 else
   if test "ECHO_C_OUT" -eq 0; then
     DASH_N=
-    BACKSLASH_C= '\\\\c'
+    BACKSLASH_C='\\\\c'
   else
     AC_MSG_ERROR("echo behaviour undetermined")
   fi