component/tcl: fix compilation for Fedora

On Fedora, the flag -lm is not correctly added so add it manually.

component/tcl/buildout.cfg

@@ -10,7 +10,7 @@ md5sum = 0e4358aade2f5db8a8b6f2f6d9481ec2
 shared = true
 environment =
   CPPFLAGS=-I${zlib:location}/include
-  LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib
+  LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib -lm
 pre-configure = rm -r pkgs/*/
 configure-command = unix/configure
 configure-options =