Fix EXT_primitive_bounding_box name string (#371)

diff --git a/extensions/EXT/EXT_primitive_bounding_box.txt b/extensions/EXT/EXT_primitive_bounding_box.txt
index 28fe4bd..a2bddf7 100644
--- a/extensions/EXT/EXT_primitive_bounding_box.txt
+++ b/extensions/EXT/EXT_primitive_bounding_box.txt
@@ -4,7 +4,7 @@
 
 Name Strings
 
-    GL_EXT_primitive_bounding box
+    GL_EXT_primitive_bounding_box
 
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