Remove rsvg-convert rule from docs makefile (#479)
diff --git a/docs/Makefile b/docs/Makefile
index 62920d0..18282b6 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -1,8 +1,4 @@
-all: index.html concepts.html reference.html security.html migration.html whats_new.html \
- generator_flow.png
-
-%.png: %.svg
- rsvg-convert $< > $@
+all: index.html concepts.html reference.html security.html migration.html whats_new.html
%.html: %.rst
rst2html --field-name-limit=32 --stylesheet=lsr.css --link-stylesheet $< $@