fix(gitmodules): update pehe submodule url to https

Signed-off-by: Charles Chin <eallion.s+github@gmail.com>

Author: eallion

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "themes/pehe"]
 	path = themes/pehe
-	url = git@github.com:eallion/pehe.git
+	url = https://github.com/eallion/pehe.git