Add dl library, bug#481060.

---

diff -urNp truecrypt-7.1a-source.org/Main/Main.make truecrypt-7.1a-source/Main/Main.make
--- truecrypt-7.1a-source.org/Main/Main.make	2012-02-07 12:36:48.000000000 +0200
+++ truecrypt-7.1a-source/Main/Main.make	2013-12-08 21:50:07.224586712 +0200
@@ -105,7 +105,7 @@ TC_VERSION = $(shell grep VERSION_STRING
 
 $(APPNAME): $(LIBS) $(OBJS)
 	@echo Linking $@
-	$(CXX) -o $(APPNAME) $(LFLAGS) $(OBJS) $(LIBS) $(FUSE_LIBS) $(WX_LIBS)
+	$(CXX) -o $(APPNAME) $(LFLAGS) $(OBJS) $(LIBS) $(FUSE_LIBS) $(WX_LIBS) -ldl
 
 ifeq "$(TC_BUILD_CONFIG)" "Release"
 ifndef NOSTRIP