Remove usage of specific profiles because of project specific options

.gitlab-ci.yml

 variables:
-    CONAN_PROFILE: "gcc7"                                                                               # profile to use with conan
+    CONAN_PROFILE: "default"                                                                            # profile to use with conan
     CONAN_BINTRAY_REMOTE_NAME: "dutiona-lrde"                                                           # Conan remote name
     CONAN_BINTRAY_REMOTE_URL: "https://api.bintray.com/conan/dutiona/lrde"                              # Conan remote name
     CONAN_BINTRAY_USER: "dutiona"                                                                       # Conan user name
@@ -24,6 +24,7 @@ stages:
         - conan create
               --build missing
               -pr $CONAN_PROFILE
+              -s compiler.libcxx=libstdc++11
               . $NAME/$VERSION@$CONAN_LRDE_USER/$TAG-$CONAN_PROFILE
 
 distcheck-build-linux-gcc7-release:
@@ -40,14 +41,12 @@ distcheck-build-linux-gcc8-release:
     variables:
         CC: "gcc-8"
         CXX: "g++-8"
-        CONAN_PROFILE: "gcc8"
 
 distcheck-build-linux-gcc8-debug:
     <<: *distcheck-basic-build-linux
     variables:
         CC: "gcc-8"
         CXX: "g++-8"
-        CONAN_PROFILE: "gcc8"
         RELEASE_TYPE: "Debug"
 
 distcheck-build-linux-clang6-release:
@@ -55,14 +54,12 @@ distcheck-build-linux-clang6-release:
     variables:
         CC: "clang-6.0"
         CXX: "clang++-6.0"
-        CONAN_PROFILE: "clang6"
 
 distcheck-build-linux-clang6-debug:
     <<: *distcheck-basic-build-linux
     variables:
         CC: "clang-6.0"
         CXX: "clang++-6.0"
-        CONAN_PROFILE: "clang6"
         RELEASE_TYPE: "Debug"
 
 distcheck-build-linux-clang7-release:
@@ -70,14 +67,12 @@ distcheck-build-linux-clang7-release:
     variables:
         CC: "clang-7"
         CXX: "clang++-7"
-        CONAN_PROFILE: "clang7"
 
 distcheck-build-linux-clang7-release:
     <<: *distcheck-basic-build-linux
     variables:
         CC: "clang-7"
         CXX: "clang++-7"
-        CONAN_PROFILE: "clang7"
         RELEASE_TYPE: "Debug"
 
 distcheck-package-linux-bintray:
@@ -91,6 +86,7 @@ distcheck-package-linux-bintray:
         - conan remote list
         - conan create
                 --build missing
+                -s compiler.libcxx=libstdc++11
                 . $NAME/$VERSION@$CONAN_BINTRAY_USER/$TAG
         - conan upload
                 --all --force --confirm --retry 10 --retry-wait 5
@@ -110,6 +106,7 @@ distcheck-package-linux-lrde:
         - conan remote list
         - conan create
                 --build missing
+                -s compiler.libcxx=libstdc++11
                 . $NAME/$VERSION@$CONAN_LRDE_USER/$TAG
         - conan upload
                 --all --force --confirm --retry 10 --retry-wait 5