Disable install/installcheck targets in doc/Makefile

Author: vitcpp

Diff for: doc/Makefile

@@ -4,6 +4,9 @@
 #
 #----------------------------------------------------------------------------
 
+NO_INSTALL := 1
+NO_INSTALLCHECK := 1
+
 ifndef PGSPHERE_VERSION
 include ../Makefile.common.mk
 ifndef PGSPHERE_VERSION
@@ -25,6 +28,7 @@ include $(top_srcdir)/contrib/contrib-global.mk
 endif
 
 .SECONDARY:
+.NOTPARALLEL:
 
 ifndef FOP
 FOP = fop