remove .txt suffix from shader source files
diff --git a/progs/glsl/bump.c b/progs/glsl/bump.c
index e42421d..a2e0916 100644
--- a/progs/glsl/bump.c
+++ b/progs/glsl/bump.c
@@ -16,8 +16,8 @@
 #include "shaderutil.h"
 
 
-static char *FragProgFile = "CH11-bumpmap.frag.txt";
-static char *VertProgFile = "CH11-bumpmap.vert.txt";
+static char *FragProgFile = "CH11-bumpmap.frag";
+static char *VertProgFile = "CH11-bumpmap.vert";
 
 /* program/shader objects */
 static GLuint fragShader;