Fix drone git@next plugin Gitea version display when building tag (#4380)

Makefile

 GOFLAGS := -i -v
 EXTRA_GOFLAGS ?=
 
-LDFLAGS := -X "main.Version=$(shell git describe --tags --always | sed 's/-/+/' | sed 's/^v//')" -X "main.Tags=$(TAGS)"
+ifneq ($(DRONE_TAG),)
+	VERSION ?= $(subst v,,$(DRONE_TAG))
+	GITEA_VERSION := $(VERSION)
+else
+	ifneq ($(DRONE_BRANCH),)
+		VERSION ?= $(subst release/v,,$(DRONE_BRANCH))
+	else
+		VERSION ?= master
+	endif
+	GITEA_VERSION := $(shell git describe --tags --always | sed 's/-/+/' | sed 's/^v//')
+endif
+
+LDFLAGS := -X "main.Version=$(GITEA_VERSION)" -X "main.Tags=$(TAGS)"
 
 PACKAGES ?= $(filter-out code.gitea.io/gitea/integrations,$(shell $(GO) list ./... | grep -v /vendor/))
 SOURCES ?= $(shell find . -name "*.go" -type f)
 	EXECUTABLE := gitea
 endif
 
-ifneq ($(DRONE_TAG),)
-	VERSION ?= $(subst v,,$(DRONE_TAG))
-else
-	ifneq ($(DRONE_BRANCH),)
-		VERSION ?= $(subst release/v,,$(DRONE_BRANCH))
-	else
-		VERSION ?= master
-	endif
-endif
-
 # $(call strip-suffix,filename)
 strip-suffix = $(firstword $(subst ., ,$(1)))