fix preview branch regex (#980)

Author: artcz

Makefile

@@ -17,7 +17,7 @@ export GIT_VERSION ?= $(shell git rev-parse --short HEAD)
 # Auto-detect and sanitize current git branch
 BRANCH ?= $(shell git rev-parse --abbrev-ref HEAD)
 # Replace "/" and other non-alphanumeric characters with "-"
-SAFE_BRANCH := $(shell echo "$(BRANCH)" | sed 's/[^A-Za-z0-9._-]/-/g')
+SAFE_BRANCH := $(shell echo "$(BRANCH)" | sed 's/[^A-Za-z0-9-]/-/g')
 FORCE_DEPLOY ?= false
 
 .PHONY: build deploy dev clean install