CI : travis-ci : prepare for using stock OpenSSL

initially SSL_LIB and SSL_INC were set globally and we assumed
that any OpenSSL variant is supposed to be built using "script/build-ssl.sh".

starting with ARM64 build we use stock openssl, also it makes sense
to use stock openssl for 1.1.1 builds for velocity sake.

Let us make stock openssl lib first class citizen.

SSL_LIB and SSL_INC are only set when custom openssl variant
is built.

.travis.yml

@@ -12,8 +12,6 @@ branches:
 env:
   global:
     - FLAGS="USE_ZLIB=1 USE_PCRE=1 USE_PCRE_JIT=1 USE_LUA=1 USE_OPENSSL=1 USE_SYSTEMD=1 USE_WURFL=1 WURFL_INC=contrib/wurfl WURFL_LIB=contrib/wurfl USE_DEVICEATLAS=1 DEVICEATLAS_SRC=contrib/deviceatlas USE_51DEGREES=1"
-    - SSL_LIB=${HOME}/opt/lib
-    - SSL_INC=${HOME}/opt/include
     - TMPDIR=/tmp
     - FIFTYONEDEGREES_SRC="contrib/51d/src/pattern"
     - DEBUG_OPTIONS="DEBUG_STRICT=1"
@@ -41,15 +39,10 @@ matrix:
     compiler: clang
     env: TARGET=linux-glibc OPENSSL_VERSION=1.1.1f CC=clang-9
   - os: linux
-    # The ARM64 build uses openssl and libssl-dev from Ubuntu repository. They come preinstalled by TravisCI!
     arch: arm64
     if: type == push
     compiler: clang
-    env: TARGET=linux-glibc OPENSSL_VERSION=1.1.1f CC=clang-9 SSL_LIB=/usr/lib SSL_INC=/usr/include
-    install:
-      - git clone https://github.com/VTest/VTest.git ../vtest
-      # Special flags due to: https://github.com/vtest/VTest/issues/12
-      - make -C ../vtest FLAGS="-O2 -s -Wall"
+    env: TARGET=linux-glibc CC=clang-9
   - os: linux
     arch: s390x
     if: type == push
@@ -115,12 +108,16 @@ install:
   - git clone https://github.com/VTest/VTest.git ../vtest
   # Special flags due to: https://github.com/vtest/VTest/issues/12
   - make -C ../vtest FLAGS="-O2 -s -Wall"
-  - travis_wait bash -c 'scripts/build-ssl.sh >build-ssl.log 2>&1' || (cat build-ssl.log && exit 1)
+  - |
+    if [ ! -z ${OPENSSL_VERSION+x} ] || [ ! -z ${LIBRESSL_VERSION+x} ] || [ ! -z ${BORINGSSL+x} ]; then
+       travis_wait bash -c 'scripts/build-ssl.sh >build-ssl.log 2>&1' || (cat build-ssl.log && exit 1)
+       export SSL_LIB=${HOME}/opt/lib SSL_INC=${HOME}/opt/include
+    fi
 
 script:
   - if [ "${CC%-*}"  = "clang" ]; then export FLAGS="$FLAGS USE_OBSOLETE_LINKER=1" DEBUG_CFLAGS="-g -fsanitize=address" LDFLAGS="-fsanitize=address"; fi
   - make -C contrib/wurfl
-  - make -j3 CC=$CC CPU_CFLAGS.generic="-O1" V=1 ERR=1 TARGET=$TARGET $FLAGS DEBUG_CFLAGS="$DEBUG_CFLAGS" LDFLAGS="$LDFLAGS" ADDLIB="-Wl,-rpath,$SSL_LIB" 51DEGREES_SRC="$FIFTYONEDEGREES_SRC" EXTRA_OBJS="$EXTRA_OBJS" $DEBUG_OPTIONS
+  - make -j3 CC=$CC CPU_CFLAGS.generic="-O1" V=1 ERR=1 TARGET=$TARGET $FLAGS DEBUG_CFLAGS="$DEBUG_CFLAGS" LDFLAGS="$LDFLAGS" $([ ! -z ${SSL_LIB+x} ] && echo ADDLIB="-Wl,-rpath,$SSL_LIB") 51DEGREES_SRC="$FIFTYONEDEGREES_SRC" EXTRA_OBJS="$EXTRA_OBJS" $DEBUG_OPTIONS
   - ./haproxy -vv
   - if [ "${TRAVIS_OS_NAME}" = "linux" ]; then ldd haproxy; fi
   - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then otool -L haproxy; fi