fix: Remove prefix

Signed-off-by: Ce Gao <gaoce@caicloud.io>

Makefile

@@ -35,7 +35,7 @@ TARGETS := katib-controller katib-db-manager suggestion-chocolate suggestion-hyp
 # The final built images are:
 #   $[REGISTRY]/$[IMAGE_PREFIX]$[TARGET]$[IMAGE_SUFFIX]:$[VERSION]
 # $[REGISTRY] is an item from $[REGISTRIES], $[TARGET] is an item from $[TARGETS].
-IMAGE_PREFIX ?= $(strip clever-)
+IMAGE_PREFIX ?= $(strip )
 IMAGE_SUFFIX ?= $(strip )
 
 # Container registries.