Fix automatic header by excluding src/precomp.hpp

Makefile

@@ -53,7 +53,7 @@ BIN := $(OUTDIR)/$(PROJ)
 SRCS += $(notdir $(wildcard src/*.cpp))
 OBJS := $(addprefix $(BUILDDIR)/, $(SRCS:.cpp=.o))
 DEPS := $(addprefix $(BUILDDIR)/, $(SRCS:.cpp=.dep))
-HDRS ?= $(wildcard src/*.hpp)
+HDRS ?= $(filter-out src/precomp.hpp,  $(wildcard src/*.hpp))
 MANS := $(addprefix $(PREFIX)/, $(wildcard man/man*/*))
 
 # if project supports plugins, link to libdl where needed